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Catalysts, Volume 14, Issue 1 (January 2024) – 91 articles

Cover Story (view full-size image): This study explores the design, synthesis, and catalytic application of a newly synthesized nitrogen-rich Zn(II) MOF (ZnMOF) for the proficient conversion of carbon dioxide into cyclic carbonates through cycloaddition to epoxides. The investigation encompasses diverse aspects, including the test of the catalytic activity of ZnMOF with various epoxides, yielding products with a notable efficiency up to 99%. The study also explores the influence of co-catalysts on the reaction, identifying tetrabutylammonium bromide (TBABr) as the most effective one. Finally, a plausible reaction mechanism is proposed aiming to shed light on the ZnMOF efficacy as a catalyst in the sustainable conversion of CO2 to cyclic carbonates. View this paper
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10 pages, 2211 KiB  
Article
Phase Transformation of Zr-Modified LaNiO3 Perovskite Materials: Effect of CO2 Reforming of Methane to Syngas
by Tatiparthi Vikram Sagar, Nakka Lingaiah, Potharaju S. Sai Prasad, Nataša Novak Tušar and Urška Lavrenčič Štangar
Catalysts 2024, 14(1), 91; https://doi.org/10.3390/catal14010091 - 22 Jan 2024
Cited by 2 | Viewed by 1102
Abstract
Zr-modified LaNiO3 catalysts (LaNixZr1−xO3; 0 ≤ x ≤ 1) are synthesized by the sol–gel method. The physio-chemical properties of materials are investigated using different characterization techniques and evaluated for the CO2 reforming of methane to [...] Read more.
Zr-modified LaNiO3 catalysts (LaNixZr1−xO3; 0 ≤ x ≤ 1) are synthesized by the sol–gel method. The physio-chemical properties of materials are investigated using different characterization techniques and evaluated for the CO2 reforming of methane to syngas. Interestingly, the characterization studies revealed the phase transformation from La-Zr pyrochlore to La-Ni perovskite depending on the Ni:Zr ratio in the material. The formation of the pyrochlore phase is observed for high-Zr-containing catalysts, thus leading to the production of bulk NiO. The formation of La-Ni perovskite is observed for high-Ni-containing catalysts and the ZrO2 acted as a support. The formation of La-Ni perovskite supported on ZrO2 enhanced the Ni dispersion of the catalysts. The high dispersion of Ni enhanced the catalytic activity, and LaNi0.8Zr0.2O3 showed the best performance among all of the studied catalysts in terms of conversions and the H2/CO ratio. Full article
(This article belongs to the Special Issue Surface Microstructure Design for Advanced Catalysts)
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11 pages, 2128 KiB  
Article
Organocatalysts for the Synthesis of Cyclic Carbonates under the Conditions of Ambient Temperature and Atmospheric CO2 Pressure
by Yeongju Seong, Sanghun Lee, Seungyeon Cho, Yoseph Kim and Youngjo Kim
Catalysts 2024, 14(1), 90; https://doi.org/10.3390/catal14010090 - 22 Jan 2024
Viewed by 1154
Abstract
2–(1H–1,2,4–Triazol–3–yl)phenol (CAT–1) was used as an organocatalyst for the coupling reaction of CO2 and epoxides at an ambient temperature and atmospheric CO2 pressure (1 bar). This compound has a structure in which a hydrogen bond donor, a [...] Read more.
2–(1H–1,2,4–Triazol–3–yl)phenol (CAT–1) was used as an organocatalyst for the coupling reaction of CO2 and epoxides at an ambient temperature and atmospheric CO2 pressure (1 bar). This compound has a structure in which a hydrogen bond donor, a hydrogen bond acceptor, and another hydrogen bond donor are adjacent in sequence in a molecule. The binary catalytic system of CAT–1/nBu4NI showed TON = 19.2 and TOF = 1.60 h−1 under 1 bar CO2 at room temperature within 12 h using 2–butyloxirane. Surprisingly, the activity of CAT–1, in which phenol and 1H–1,2,4–triazole are chemically linked, showed a much greater synergistic effect than when simply mixing the same amount of phenol and 1H–1,2,4–triazole under the same reaction conditions. In addition, our system showed a broad terminal and internal epoxide substrate scope. Full article
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16 pages, 5621 KiB  
Article
Catalytic Reductive Degradation of 4-Nitrophenol and Methyl orange by Novel Cobalt Oxide Nanocomposites
by Hawra A. Bukhamsin, Hassan H. Hammud, Chawki Awada and Thirumurugan Prakasam
Catalysts 2024, 14(1), 89; https://doi.org/10.3390/catal14010089 - 21 Jan 2024
Cited by 2 | Viewed by 1458
Abstract
Cobalt oxide nanocomposites were synthesized and used for the catalytic degradation of 4-nitrophenol (4-NP) and methyl orange (MO). Cobalt oxide nanocomposites PyroHAB9 was prepared by heating cobalt acetylacetonate complex HAB9 at 300 °C, while PyroHAB19 was prepared by heating cobalt acetylacetonate–carboxymethyl cellulose complex [...] Read more.
Cobalt oxide nanocomposites were synthesized and used for the catalytic degradation of 4-nitrophenol (4-NP) and methyl orange (MO). Cobalt oxide nanocomposites PyroHAB9 was prepared by heating cobalt acetylacetonate complex HAB9 at 300 °C, while PyroHAB19 was prepared by heating cobalt acetylacetonate–carboxymethyl cellulose complex at 300 °C. FTIR indicated the presence of Co3O4 species, while Raman spectrum indicated the presence of graphite in PyroHAB19. The SEM morphology of nanocomposites exhibited irregular spherical shape nanoparticles with sizes ranging between 20 to 60 nm. Additionally, nanowires were also seen in HAB19. Also, 2Ɵ peaks in PXRD revealed the formation of Co3O4 in HAB19. Cyclic voltammetry indicated enhanced electrochemical redox activity of HAB19. The structures of the nanocomposites were related to their catalytic activities. The turnover frequency (TOF) values of the catalytic reduction of p-nitrophenol (P-NP) and methyl orange (MO) were greater for HAB19 compared to HAB9 nano-catalysts. Also, the TOF values of the catalytic reduction of MO were greater than that of P-NP by both nano-catalysts. It is obvious that the rate constants of catalytic reductions for MO by metal oxide nanocomposites were greater than the corresponding rate constants for PNP. The highest rate constant was found for PyroHAB19 in MO reduction. Full article
(This article belongs to the Special Issue Design and Synthesis of Nanostructured Catalysts, 2nd Edition)
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14 pages, 2681 KiB  
Article
Hydrocarbon-Rich Bio-Oil Production from Ex Situ Catalytic Microwave Co-Pyrolysis of Peanut Shells and Low-Density Polyethylene over Zn-Modified Hierarchical Zeolite
by Zheng Dong, Yuanchong Yue, Jianmei Bai, Kun Chen, Mei Wang and Quan Bu
Catalysts 2024, 14(1), 88; https://doi.org/10.3390/catal14010088 - 21 Jan 2024
Viewed by 1205
Abstract
Peanut shells, a major economic and oil crop in China, boast an abundant availability and remarkably high lignin content compared to other agricultural residues. Previous work indicated that the modified hierarchical zeolite (Zn-ZSM-5/MCM41) was effective in promoting the conversion of intermediate macromolecules during [...] Read more.
Peanut shells, a major economic and oil crop in China, boast an abundant availability and remarkably high lignin content compared to other agricultural residues. Previous work indicated that the modified hierarchical zeolite (Zn-ZSM-5/MCM41) was effective in promoting the conversion of intermediate macromolecules during the lignin pyrolysis reaction and enhancing the yield and selectivity of liquid products. Thereby, this study aims to improve the quality of liquid products in the ex situ catalytic microwave co-pyrolysis of peanut shells and LDPE by utilizing Zn-ZSM-5/MCM41. Employing a compound center experimental design, we optimized reaction conditions through response surface analysis. The impact of microwave pyrolysis temperature and the catalyst-to-feedstock ratio on yield distribution and liquid product selectivity was explored. Results indicated a marginal increase in liquid product yield with rising pyrolysis temperatures. Moreover, an initial increase followed by a subsequent decrease in liquid product yield was observed with an increase in the catalyst-to-feedstock ratio. Optimal conditions of 450 °C and a catalyst-to-peanut hull ratio of 2.34% yielded the highest bio-oil yield at 34.25%. GC/MS analysis of the bio-oil revealed a peak in hydrocarbon content at 68.36% under conditions of 450 °C and a catalyst-to-feedstock ratio of 13.66%. Additionally, the quadratic model effectively predicted bio-oil yield and the selectivity for major chemical components. This study underscores the potential of Zn-ZSM-5/MCM41 in optimizing liquid product quality during catalytic co-pyrolysis, offering insights into bio-oil production and its chemical composition. Full article
(This article belongs to the Special Issue Catalytic Pyrolysis of Lignocellulosic Biomass)
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22 pages, 4320 KiB  
Article
Water Oxidation over Au-Pd/TiO2 as a Substitute for Iridium-Based Catalysts
by Khaja Wahab and Hicham Idriss
Catalysts 2024, 14(1), 87; https://doi.org/10.3390/catal14010087 - 21 Jan 2024
Cited by 1 | Viewed by 938
Abstract
Water oxidation is one of the most important reactions needed for a transition to a green economy. The reaction relies on extracting electrons from oxygen anions and is commonly studied using homogenous catalysts based on Ru or Ir metals. Because of Ir scarcity [...] Read more.
Water oxidation is one of the most important reactions needed for a transition to a green economy. The reaction relies on extracting electrons from oxygen anions and is commonly studied using homogenous catalysts based on Ru or Ir metals. Because of Ir scarcity and its relative instability in acidic environments, metals to replace it are sought after. In this study, we have synthesized Au-Pd-based catalysts deposited on TiO2 with different ratios in order to mimic IrO2 valence orbitals (Ir5d) by the hybrid valence orbitals of Au5d and Pd4d and compared their heterogeneous catalytic activity for the evolution of O2 from water in the presence of cerium ammonium nitrate (CAN). Au-Pd-based catalysts were found to be active at a particular nominal atomic ratio. At an atomic ratio of 1 Au to 2 Pd and 1 Au to 3 Pd, the catalysts were active and stable for oxygen production from water. Long-term runs up to 20,000 min still showed the expected stoichiometry between O2 production and CAN consumption (1 to 4). However, catalysts with a reverse ratio were not active. Also, the monometallic catalysts were found to be not active for the reaction. We link the reason for the activity of Au-Pd with this specific ratio to the shape and energy position of their valence band that might be similar to those of IrO2 particles. While the turnover numbers of the Au-Pd-based catalysts were found to be lower than those of IrO2-based catalysts, on the same support in a heterogenous system, there is considerable potential upon further optimization for these two metals to replace IrO2 for a water oxidation reaction. Full article
(This article belongs to the Special Issue Feature Papers in Catalytic Materials)
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12 pages, 1653 KiB  
Article
Catalytic Conversion of Cyclopentanone into Dimethyl Adipate over Solid Basic Catalysts with Dimethyl Carbonate
by Irene Martínez-Salazar, Ana Orozco-Saumell, Manuel López Granados and Rafael Mariscal
Catalysts 2024, 14(1), 86; https://doi.org/10.3390/catal14010086 - 20 Jan 2024
Viewed by 1249
Abstract
The synthesis of dimethyl adipate (DAP), a stable configuration of adipic acid, from biomass-derived cyclopentanone (CPO) and dimethyl carbonate (DMC) constitutes an attractive greener route than petroleum-based industrial processes. Solid basic catalysts such as MgO, Mg5(CO3)4(OH)2 [...] Read more.
The synthesis of dimethyl adipate (DAP), a stable configuration of adipic acid, from biomass-derived cyclopentanone (CPO) and dimethyl carbonate (DMC) constitutes an attractive greener route than petroleum-based industrial processes. Solid basic catalysts such as MgO, Mg5(CO3)4(OH)2·4H2O, KOCH3 and Ca(OCH3)2 have been used achieving a DAP yield up to 30% at 533 K. In addition to the type of catalyst, other operating conditions such as the substrate, reaction time, temperature and CPO concentration have been studied. The methylation of DAP and CPO and the self-aldol condensation of CPO to form dimers and oligomers are reactions that occur in parallel with the production of DAP. It has been established that the main challenge is the self-aldol condensation of CPO. It has been identified that at short reaction times, to prevent methylation, and at dilute concentrations, to avoid CPO self-condensation, the DAP formation rate is much higher than these other competitive reactions. Finally, it should be noted that a DAP productivity up to 3.45 g·gcat−1·h−1 has been achieved under mild conditions. Full article
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16 pages, 4003 KiB  
Article
3D-Printed Monoliths Based on Cu-Exchanged SSZ-13 as Catalyst for SCR of NOx
by Elisabetta M. Cepollaro, Stefano Cimino, Marco D’Agostini, Nicola Gargiulo, Giorgia Franchin and Luciana Lisi
Catalysts 2024, 14(1), 85; https://doi.org/10.3390/catal14010085 - 19 Jan 2024
Viewed by 1022
Abstract
Monoliths manufactured by Direct Ink Writing containing 60% SSZ-13 (SiO2/Al2O3 = 23) and SiO2 with 10% laponite as a binder were investigated as self-standing structured catalysts for NH3-SCR of NOx after a short (4 [...] Read more.
Monoliths manufactured by Direct Ink Writing containing 60% SSZ-13 (SiO2/Al2O3 = 23) and SiO2 with 10% laponite as a binder were investigated as self-standing structured catalysts for NH3-SCR of NOx after a short (4 h) and prolonged (24 h) ion exchange with copper and then compared with pure SSZ-13 exchanged under the same conditions. The catalysts were characterized by morphological (XRD and SEM), textural (BET and pore size distribution), chemical (ICP-MS), red-ox (H2-TPR), and surface (NH3-TPD) analyses. The silica-based binder uniformly covered the SSZ-13 particles, and copper was uniformly distributed as well. The main features of the pure Cu-exchanged SSZ-13 zeolite were preserved in the composite monoliths with a negligible contribution of the binder fraction. NH3-SCR tests, carried out on both monolithic and powdered samples in the temperature range of 70–550 °C, showed that composite monoliths provided very good activity, and that the intrinsic activity of SSZ-13 was enhanced by the hierarchical structure of the composite material. Full article
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29 pages, 9554 KiB  
Review
Biocatalysis for the Synthesis of Active Pharmaceutical Ingredients in Deep Eutectic Solvents: State-of-the-Art and Prospects
by Ningning Zhang, Pablo Domínguez de María and Selin Kara
Catalysts 2024, 14(1), 84; https://doi.org/10.3390/catal14010084 - 19 Jan 2024
Cited by 3 | Viewed by 2822
Abstract
Biocatalysis holds immense potential for pharmaceutical development as it enables synthetic routes to various chiral building blocks with unparalleled selectivity. Therein, solvent and water use account for a large contribution to the environmental impact of the reactions. In the spirit of Green Chemistry [...] Read more.
Biocatalysis holds immense potential for pharmaceutical development as it enables synthetic routes to various chiral building blocks with unparalleled selectivity. Therein, solvent and water use account for a large contribution to the environmental impact of the reactions. In the spirit of Green Chemistry, a transition from traditional highly diluted aqueous systems to intensified non-aqueous media to overcome limitations (e.g., water shortages, recalcitrant wastewater treatments, and low substrate loadings) has been observed. Benefiting from the spectacular advances in various enzyme stabilization techniques, a plethora of biotransformations in non-conventional media have been established. Deep eutectic solvents (DESs) emerge as a sort of (potentially) greener non-aqueous medium with increasing use in biocatalysis. This review discusses the state-of-the-art of biotransformations in DESs with a focus on biocatalytic pathways for the synthesis of active pharmaceutical ingredients (APIs). Representative examples of different enzyme classes are discussed, together with a critical vision of the limitations and discussing prospects of using DESs for biocatalysis. Full article
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14 pages, 3915 KiB  
Article
An Analysis of Fixed-Bed Catalytic Reactors Performances for One-Stage Butadiene Synthesis from Ethanol
by Alma Valentina Brosteanu, Ionut Banu and Grigore Bozga
Catalysts 2024, 14(1), 83; https://doi.org/10.3390/catal14010083 - 18 Jan 2024
Viewed by 1039
Abstract
The present study assesses, using a theoretical approach, the performances of two widely used fixed-bed reactors for the ethanol-to-butadiene (ETB) one-stage (Lebedev) process: multibed adiabatic reactors (MBAR) with inter-bed heating and a multitubular reactor (MTR). The mathematical model consists of mass and heat [...] Read more.
The present study assesses, using a theoretical approach, the performances of two widely used fixed-bed reactors for the ethanol-to-butadiene (ETB) one-stage (Lebedev) process: multibed adiabatic reactors (MBAR) with inter-bed heating and a multitubular reactor (MTR). The mathematical model consists of mass and heat conservation equations at catalyst particle and particle bed scales, coupled with a published kinetic model specific for a modified MgO–SiO2 catalyst. The process simulations at the level of catalyst particle have shown that the inter-phase concentration and temperature gradients are negligible, the only physical step with a limiting influence on process kinetics being the internal diffusion. A simplified version of the reactor model was also formulated, including empirical expressions developed in the study for the calculation of internal effectiveness factors. The reactor simulations highlighted that the MBAR with inter-bed heating by injection of hot reactants provides worse butadiene (BD) yields as a consequence of reduced reaction times (due to reactant by-pass of catalyst beds). The MBAR with inter-bed heating using heat exchangers provides better performances but inferior to those of MTR if the number of catalyst beds is less than six. A preliminary optimization study for the MBAR and MTR is also presented. The results showed that the maximization of BD yield has the drawback of a low BD production rate, whereas the maximization of BD production rate corresponds to a relatively low BD yield and high ethanol and inert recycles. A trade-off between the two extreme cases can be attained by maximizing the income generated by reactor operation. Full article
(This article belongs to the Section Catalytic Reaction Engineering)
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19 pages, 5424 KiB  
Article
Insights into the Mechanism, Regio-/Diastereoselectivities and Ligand Role of Nickel-Initiated [3+2] Cycloadditions between Vinylcyclopropane and N-Tosylbenzaldimine
by Weihua Mu, Lin Zhu, Shuya Xia, Xue Tan, Liangfei Duan, Guanghao Meng and Guo Liu
Catalysts 2024, 14(1), 82; https://doi.org/10.3390/catal14010082 - 18 Jan 2024
Viewed by 881
Abstract
Density functional theory (DFT) was employed to explore the reaction mechanism, regio- and diastereoselectivities of nickel-initiated [3+2] cycloaddition between vinylcyclopropane (VCP) and N-tosylbenzaldimine assisted by phosphine ligands. Four different binding modes of the nickel center to VCP substrate were explored during the [...] Read more.
Density functional theory (DFT) was employed to explore the reaction mechanism, regio- and diastereoselectivities of nickel-initiated [3+2] cycloaddition between vinylcyclopropane (VCP) and N-tosylbenzaldimine assisted by phosphine ligands. Four different binding modes of the nickel center to VCP substrate were explored during the ring-opening of VCP, among which the C,C_anti and C,C_syn modes were verified to be the most accessible ones. Further explorations about four different phosphine ligand-assisted reactions based on the two most probable binding modes show that the difference in binding mode of bi- and monodentate phosphine ligands can vary the optimal reaction pathway, especially in the [3+2] cycloaddition process between the ring-opened intermediate and N-tosylbenzaldimine. The formation of C–C and C–N bonds between N-tosylbenzaldimine and the ring-opened intermediate through [3+2] cycloaddition is found to be stepwise, with the former acting as the rate-determining step (RDS) in most cases. Computed free energy barriers of RDS transition states on the optimal path I or II not only give out good predictions for reaction rates and half-lives, but also provide reasonable explanations for the major generation of cis-pyrrolidine. Noncovalent interaction analyses of key stationary points suggest the rate is influenced by both electronic effects and steric hindrance, while the diastereoselectivity is mainly controlled by electronic effects. Full article
(This article belongs to the Special Issue Organometallic Homogeneous Catalysis)
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19 pages, 2014 KiB  
Article
A Cluster-Type Self-Healing Catalyst for Stable Saline–Alkali Water Splitting
by Haiming Wang and Sheng Chen
Catalysts 2024, 14(1), 81; https://doi.org/10.3390/catal14010081 - 18 Jan 2024
Viewed by 964
Abstract
In electrocatalytic processes, traditional powder/film electrodes inevitably suffer from damage or deactivation, reducing their catalytic performance and stability. In contrast, self-healing electrocatalysts, through special structural design or composition methods, can automatically repair at the damaged sites, restoring their electrocatalytic activity. Here, guided by [...] Read more.
In electrocatalytic processes, traditional powder/film electrodes inevitably suffer from damage or deactivation, reducing their catalytic performance and stability. In contrast, self-healing electrocatalysts, through special structural design or composition methods, can automatically repair at the damaged sites, restoring their electrocatalytic activity. Here, guided by Pourbaix diagrams, foam metal was activated by a simple cyclic voltammetry method to synthesize metal clusters dispersion solution (MC/KOH). The metal clusters-modified hydroxylated Ni-Fe oxyhydroxide electrode (MC/NixFeyOOH) by a facile Ni-Fe metal–organic framework-reconstructed strategy, exhibiting superior performance toward the oxygen evolution reaction (OER) in the mixture of MC/KOH and saline–alkali water (MC/KOH+SAW). Specifically, using a nickel clusters-modified hydroxylated Ni-Fe oxyhydroxide electrode (NC/NixFeyOOH) for OER, the NC/NixFeyOOH catalyst has an ultra-low overpotential of 149 mV@10 mA cm−2, and durable stability of 100 h at 500 mA cm−2. By coupling this OER catalyst with an efficient hydrogen evolution reaction catalyst, high activity and durability in overall SAW splitting is exhibited. What is more, benefiting from the excellent fluidity, flexibility, and enhanced catalytic activity effect of the liquid NC, we demonstrate a self-healing electrocatalysis system for OER operated in the flowing NC/(KOH+SAW). This strategy provides innovative solutions for the fields of sustainable energy and environmental protection. Full article
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5 pages, 198 KiB  
Editorial
CO2 Capture, Utilization and Storage: Catalysts Design
by Leonarda Francesca Liotta and Hongjing Wu
Catalysts 2024, 14(1), 80; https://doi.org/10.3390/catal14010080 - 18 Jan 2024
Cited by 1 | Viewed by 1224
Abstract
Today, the problem of CO2 emission into the atmosphere is one of the most urgent and complex challenges facing humanity [...] Full article
(This article belongs to the Special Issue CO2 Capture, Utilization and Storage: Catalysts Design)
17 pages, 9238 KiB  
Article
Influence of the La0.2Sr0.7Ti0.95Ni0.05O3 (LSTN) Synthesis Method on SOFC Anode Performance
by Moran Dahan, Ludmila Fadeev, Hagay Hayun, Michael Gozin, Yaniv Gelbstein and Brian A. Rosen
Catalysts 2024, 14(1), 79; https://doi.org/10.3390/catal14010079 - 18 Jan 2024
Viewed by 1040
Abstract
Solid oxide fuel cells are characterized by a high efficiency for converting chemical energy into electricity and fuel flexibility. This research work focuses on developing durable and efficient anodes for solid oxide fuel cells (SOFCs) based on exsolving nickel from the perovskite structure. [...] Read more.
Solid oxide fuel cells are characterized by a high efficiency for converting chemical energy into electricity and fuel flexibility. This research work focuses on developing durable and efficient anodes for solid oxide fuel cells (SOFCs) based on exsolving nickel from the perovskite structure. A-site-deficient La- and Ni-doped strontium titanates (La0.2Sr0.7Ti0.95Ni0.05O3−δ, LSTN) were synthesized using four different techniques and mixed with Ce0.8Gd0.2O2−δ (GDC) to form the SOFC anode. The synthesis routes of interest for comparison included solid-state, sol-gel, hydrothermal, and co-precipitation methods. LSTN powders were characterized via XRD, SEM, TPR, BET and XPS. In situ XRD during reduction was measured and the reduced powders were analyzed using TEM. The impact of synthesis route on SOFC performance was investigated. All samples were highly durable when kept at 0.5 V for 48 h at 800 °C with H2 fuel. Interestingly, the best performance was observed for the cell with the LSTN anode prepared via co-precipitation, while the conventional solid-state synthesis method only achieved the second-best results. Full article
(This article belongs to the Topic Advances in Inorganic Synthesis)
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16 pages, 5344 KiB  
Article
Surface Modification of Fe-ZSM-5 Using Mg for a Reduced Catalytic Pyrolysis Temperature of Low-Density Polyethylene to Produce Light Olefin
by Yincui Li, Ting Liu, Shengnan Deng, Xiao Liu, Qian Meng, Mengxue Tang, Xueying Wu and Huawei Zhang
Catalysts 2024, 14(1), 78; https://doi.org/10.3390/catal14010078 - 18 Jan 2024
Viewed by 1527
Abstract
Although the catalytic pyrolysis of low-density polyethylene (LDPE) to produce light olefin has shown potential industrial application advantages, it has generally suffered when using higher pyrolysis temperatures. In this work, Mg-modified Fe-ZSM-5 was used for catalytic conversion of LDPE to obtain light olefin [...] Read more.
Although the catalytic pyrolysis of low-density polyethylene (LDPE) to produce light olefin has shown potential industrial application advantages, it has generally suffered when using higher pyrolysis temperatures. In this work, Mg-modified Fe-ZSM-5 was used for catalytic conversion of LDPE to obtain light olefin in a fixed bed reactor. The effects of catalyst types, pyrolysis temperatures, and Mg loading on the yield of light olefin were investigated. The 1 wt% Mg loading slightly improved the yield of light olefin to 38.87 wt% at 395 °C, lowering the temperature of the pyrolysis reaction. We considered that the higher light olefin yield of Fe-Mg-ZSM-5 was attributed to the introduction of Mg, where Mg regulated the surface acidity of the catalyst, inhibited the secondary cracking reaction, and reduced coking during the pyrolysis process. Furthermore, the addition of Mg also dramatically reduced the average particle size of Fe oxides from 40 nm to 10 nm, which is conducive to a lower catalytic reaction temperature. Finally, the spent catalyst could be easily regenerated at the conditions of 600 °C in airflow with a heating rate of 10 °C/min for 1 h, and the light olefin yield remained higher than 36.71 wt% after five cycles, indicating its excellent regeneration performance. Full article
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19 pages, 18285 KiB  
Article
Surface Redox Reaction for the Synthesis of NiPt Catalysts for the Upgrading of Renewable Ethanol/Methanol Mixtures
by Joachim Pasel, Friederike Woltmann, Johannes Häusler and Ralf Peters
Catalysts 2024, 14(1), 77; https://doi.org/10.3390/catal14010077 - 17 Jan 2024
Viewed by 916
Abstract
Mixtures of ethanol and methanol being synthesized from CO2 and green H2 can serve as sustainable base chemicals for a number of chemical processes. Amongst these processes, the catalytically supported synthesis of CO2-neutral C4 to C10 alcohols [...] Read more.
Mixtures of ethanol and methanol being synthesized from CO2 and green H2 can serve as sustainable base chemicals for a number of chemical processes. Amongst these processes, the catalytically supported synthesis of CO2-neutral C4 to C10 alcohols is of increasing importance as, e.g., iso-butanol can be used as a drop-in fuel or after dehydration to produce iso-butene as a feedstock for the synthesis of plastics. 2-ethyl-hexanol can be further refined into solvents, tensides, or monomers. In this respect, NiPt alloys on an activated carbon support were found to be active and stable catalysts for the synthesis of iso-butanol following the Guerbet reaction scheme. In this study, two different routes are applied to the synthesis of these NiPt catalysts: a more conventional one based on the impregnation of Ni and Pt salts and an advanced path with a surface redox reaction between elemental Ni on the support and Pt ions in a polar solution. The experimental evaluation shows that the Pt particles from the surface redox reaction being exposed on the Ni particles are more active than those on the impregnated catalysts due to their high surface energy. Their specific space-time yields are 10–20 times higher. Full article
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12 pages, 2036 KiB  
Article
Effect of the Heterovalent Sc3+ and Nb5+ Doping on Photoelectrochemical Behavior of Anatase TiO2
by Elena S. Siliavka, Aida V. Rudakova, Tair V. Bakiev, Anna A. Murashkina, Petr D. Murzin, Galina V. Kataeva, Alexei V. Emeline and Detlef W. Bahnemann
Catalysts 2024, 14(1), 76; https://doi.org/10.3390/catal14010076 - 17 Jan 2024
Viewed by 899
Abstract
In this study, we explored the effect of either Nb or Sc doping at a concentration range of 0.0–1.0 at.% on the physical–chemical and photoelectrochemical behavior of TiO2 anatase electrodes. This behavior was characterized by work function, flat band potential, donor density, [...] Read more.
In this study, we explored the effect of either Nb or Sc doping at a concentration range of 0.0–1.0 at.% on the physical–chemical and photoelectrochemical behavior of TiO2 anatase electrodes. This behavior was characterized by work function, flat band potential, donor density, spectral dependence of photocurrent and stationary photocurrent measurements. All experimental results are interpreted in terms of the formation of the shallow delocalized polaron states in the case of Nb doping and deep acceptor states induced by Sc doping on TiO2 anatase. Full article
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19 pages, 3920 KiB  
Review
Preparation of Mesoporous Zeolites and Their Applications in Catalytic Elimination of Atmospheric Pollutants
by Chuchen Miao, Lanyi Wang, Shengran Zhou, Di Yu, Chunlei Zhang, Siyu Gao, Xuehua Yu and Zhen Zhao
Catalysts 2024, 14(1), 75; https://doi.org/10.3390/catal14010075 - 17 Jan 2024
Cited by 1 | Viewed by 1230
Abstract
With increasing environmental awareness, the issue of atmospheric pollution has gained significant attention. Specifically, three types of atmospheric pollutants, namely, nitrogen oxides, volatile organic compounds, and carbon monoxide, have become the focus of widespread concern. In addressing these pollutants, mesoporous zeolites have emerged [...] Read more.
With increasing environmental awareness, the issue of atmospheric pollution has gained significant attention. Specifically, three types of atmospheric pollutants, namely, nitrogen oxides, volatile organic compounds, and carbon monoxide, have become the focus of widespread concern. In addressing these pollutants, mesoporous zeolites have emerged as promising materials due to their large specific surface area, which enables effective dispersion of active sites, and their large pore volume, which facilitates efficient diffusion. This article provides a comprehensive overview of the preparation methods of mesoporous zeolites and their applications in removing nitrogen oxides, volatile organic compounds, and carbon monoxide. It also highlights the challenges and limitations faced by the application of mesoporous zeolites in pollutant removal and emphasizes their potential as efficient catalysts. Full article
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11 pages, 1353 KiB  
Article
Sulfonic Resins as Catalysts for the Oxidation of Alcohols with H2O2/KBr
by Vicente Dorado, Clara I. Herrerías and José M. Fraile
Catalysts 2024, 14(1), 74; https://doi.org/10.3390/catal14010074 - 17 Jan 2024
Viewed by 985
Abstract
Sulfonic resins can replace homogeneous sulfonic acids in the oxidation of alcohols with the H2O2/KBr system. The performance of different resins was tested with methyl 9(10)-hydroxystearate, a secondary fatty alcohol. The structural features of the resin were more important [...] Read more.
Sulfonic resins can replace homogeneous sulfonic acids in the oxidation of alcohols with the H2O2/KBr system. The performance of different resins was tested with methyl 9(10)-hydroxystearate, a secondary fatty alcohol. The structural features of the resin were more important than the acid strength for the catalytic performance of this reaction. The optimization of the reaction conditions allows the recovery of the resin, although regeneration is required due to the active role of KBr, and a significant loss of sulfonic groups can be detected after nine runs. In the case of primary fatty alcohols, the oxidation leads to carboxylic acids, which are esterified with the starting alcohol under the acidic conditions. For cyclic secondary alcohols, the steric hindrance around the hydroxyl group seems to be important for the efficiency of the oxidation to ketone. Full article
(This article belongs to the Special Issue Advances in the Catalytic Behavior of Ion-Exchange Resins)
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16 pages, 15264 KiB  
Article
Dyes Degradation Using Cooper-Nickel Ferrite and Its Tunable Structural and Photocatalytic Properties
by Ila Gabriele Diniz Dias de Azevedo, Marco Antonio Morales Torres, Carlson Pereira de Souza and André Luis Lopes Moriyama
Catalysts 2024, 14(1), 73; https://doi.org/10.3390/catal14010073 - 17 Jan 2024
Viewed by 895
Abstract
Water pollution is a serious worldwide problem. Among its pollutants, dyes that are overused by various types of industries and are resistant to conventional effluent treatments stand out. In this study, mixed copper and nickel ferrites NixCu(1-x)Fe2O [...] Read more.
Water pollution is a serious worldwide problem. Among its pollutants, dyes that are overused by various types of industries and are resistant to conventional effluent treatments stand out. In this study, mixed copper and nickel ferrites NixCu(1-x)Fe2O4 (x = 0, 0.2, 0.4, 0.6, 0.8 e 1.0), were produced by the EDTA-Citrate complexation method, characterized and applied in photocatalysis with methylene blue (MB) and rhodamine B (RhB) dyes, varying the reaction pH between 2, 6 and 10. The ferrites with the highest percentages of copper had a tetragonal structure, while those with the highest percentages of nickel had a cubic structure, all with inverse spinel and all presenting bandgap values lower than 2 eV. Samples with higher percentages of copper (x = 0 and 0.2) at pH 10 showed degradation of approximately 55% for RhB and 40% for MB. A mixture of MB and RhB was also evaluated, showing a greater removal of methylene blue due to its preferential adsorption on the surface of the material. In this way, mixed copper and nickel ferrites proved promising as catalysts in photocatalytic processes. Full article
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1 pages, 136 KiB  
Correction
Correction: Hasan et al. Synthesizing and Characterizing a Mesoporous Silica Adsorbent for Post-Combustion CO2 Capture in a Fixed-Bed System. Catalysts 2023, 13, 1267
by Hind F. Hasan, Farah T. Al-Sudani, Talib M. Albayati, Issam K. Salih, Hamed N. Harharah, Hasan Sh. Majdi, Noori M. Cata Saady, Sohrab Zendehboudi and Abdelfattah Amari
Catalysts 2024, 14(1), 72; https://doi.org/10.3390/catal14010072 - 17 Jan 2024
Viewed by 647
Abstract
In the original publication [...] Full article
22 pages, 6286 KiB  
Article
Fe3O4-CdO Nanocomposite for Organic Dye Photocatalytic Degradation: Synthesis and Characterization
by Ahlam Albeladi, Zaheer Khan, Shaeel Ahmed Al-Thabaiti, Rajan Patel, Maqsood Ahmad Malik and Shilpa Mehta
Catalysts 2024, 14(1), 71; https://doi.org/10.3390/catal14010071 - 17 Jan 2024
Cited by 1 | Viewed by 1350
Abstract
In this study, pure CdO nanoparticles, magnetic Fe3O4 nanoparticles, and Fe3O4-CdO nanocomposites were prepared via a solution combustion method using cetyltrimethylammonium bromide (CTAB) as a template. These prepared nanomaterial samples were characterized by X-ray diffraction (XRD), [...] Read more.
In this study, pure CdO nanoparticles, magnetic Fe3O4 nanoparticles, and Fe3O4-CdO nanocomposites were prepared via a solution combustion method using cetyltrimethylammonium bromide (CTAB) as a template. These prepared nanomaterial samples were characterized by X-ray diffraction (XRD), ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron microscopy (XPS), transmittance electron microscopy (TEM), and scanning electron microscopy (SEM) analysis. XRD patterns confirmed the purity and the crystalline nature of the prepared samples. FTIR and Raman spectra observed the metal-oxygen (M-O) bond formation. UV-vis DRS studies were performed to investigate the optical properties and the bandgap energy determination. The surface morphology and the size of the pure CdO nanoparticles, magnetic Fe3O4, and nanocomposites of Fe3O4-CdO were determined via TEM and SEM analysis. Under optimum experimental conditions, the Fe3O4-CdO nanocomposites were applied for photocatalytic activity against Methylene blue dye. Under visible light irradiation, Fe3O4-CdO nanostructures showed an efficient photocatalytic degradation of 92% against Methylene blue organic dye and showed excellent stability for multiple cycles of reuse. Full article
(This article belongs to the Special Issue Photocatalytic Nanomaterials for Environmental Purification)
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16 pages, 6946 KiB  
Article
Enhancing Catalytic Efficiency in Long-Chain Linear α-Olefin Epoxidation: A Study of CaSnO3-Based Catalysts
by Min Zhang, Hongwei Xiang and Xiaodong Wen
Catalysts 2024, 14(1), 70; https://doi.org/10.3390/catal14010070 - 17 Jan 2024
Viewed by 936
Abstract
This investigation explores the synthesis of advanced catalysts for epoxidizing long-chain linear α-olefins, a pivotal process in the chemical industry for generating critical intermediates. Employing a hydrothermal technique, we developed four distinct catalysts (CS-1–4), methodically modulating the Ca/Sn ratio to elucidate its impact [...] Read more.
This investigation explores the synthesis of advanced catalysts for epoxidizing long-chain linear α-olefins, a pivotal process in the chemical industry for generating critical intermediates. Employing a hydrothermal technique, we developed four distinct catalysts (CS-1–4), methodically modulating the Ca/Sn ratio to elucidate its impact on the catalysts’ physicochemical properties. Our research uncovered that an escalated Ca/Sn ratio induces a morphological shift from octagonal to cubic structures, concomitant with a diminution in particle size and an enhancement in specific surface area. Significantly, the CS-3 catalyst outperformed others in 1-octene epoxidation, an efficacy attributed to its augmented surface alkalinity and proliferation of medium-strength alkaline sites, likely emanating from increased surface oxygen defects. Subsequent hydrogen reduction of CS-3 further amplified these oxygen defects, yielding a 10% uptick in catalytic activity. This correlation underscores the potential of oxygen defect manipulation in optimizing catalytic efficiency. Our findings contribute a novel perspective to the development of robust, high-performance catalysts for α-olefin epoxidation, seamlessly aligning with the principles of sustainable chemistry. Full article
(This article belongs to the Special Issue Advanced Research of Perovskite Materials as Catalysts)
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23 pages, 4563 KiB  
Review
Advances in Cross-Coupling Reactions Catalyzed by Aromatic Pincer Complexes Based on Earth-Abundant 3d Metals (Mn, Fe, Co, Ni, Cu)
by Jesús Antonio Cruz-Navarro, Arturo Sánchez-Mora, Juan S. Serrano-García, Andrés Amaya-Flórez, Raúl Colorado-Peralta, Viviana Reyes-Márquez and David Morales-Morales
Catalysts 2024, 14(1), 69; https://doi.org/10.3390/catal14010069 - 16 Jan 2024
Cited by 1 | Viewed by 1613
Abstract
The increase of noble-metal-free catalysis in organic chemistry is a trending topic in constant growth due to the price increase of noble metals and their scarce abundance. As a result, many earth-abundant transition-metal complexes containing nickel, iron, or cobalt have been successfully applied [...] Read more.
The increase of noble-metal-free catalysis in organic chemistry is a trending topic in constant growth due to the price increase of noble metals and their scarce abundance. As a result, many earth-abundant transition-metal complexes containing nickel, iron, or cobalt have been successfully applied in the homogeneous catalysis of a wide number of cross-coupling reactions, and the use of pincer complexes based on these earth-abundant metals was recently explored, affording interesting results. Thus, this review provides a general overview of earth-abundant 3D pincer complexes and their application during the last decade as catalysts in cross-coupling reactions such as Kumada–Corriu, Suzuki–Miyaura, Sonogashira, C–S cross-coupling, and C–N bond-forming reactions. Full article
(This article belongs to the Special Issue Organometallic Homogeneous Catalysis)
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4 pages, 189 KiB  
Editorial
Mono- and Bimetallic Nanoparticles in Catalysis
by Elena A. Redina and Olga A. Kirichenko
Catalysts 2024, 14(1), 68; https://doi.org/10.3390/catal14010068 - 16 Jan 2024
Cited by 2 | Viewed by 1022
Abstract
The catalytic applications of supported mono- and bimetallic nanoparticles are wide on the laboratory, pilot plant and industrial scale [...] Full article
(This article belongs to the Special Issue Mono- and Bimetallic Nanoparticles in Catalysis)
12 pages, 2061 KiB  
Article
Synergistic Effect of Structure and Morphology of ZSM-5 Catalysts on the Transformation of Methanol to Propylene
by Wei Zhang, Kangzhou Wang, Xinhua Gao, Xiaojing Yong and Yanlong Gu
Catalysts 2024, 14(1), 67; https://doi.org/10.3390/catal14010067 - 15 Jan 2024
Viewed by 1163
Abstract
Here, the efficient synthesis of propylene from methanol was achieved using a series of HZSM-5 catalysts. The effect of the structure and morphology of ZSM-5 on the conversion of methanol to propylene was studied. The structure and physicochemical properties of the synthesized catalysts [...] Read more.
Here, the efficient synthesis of propylene from methanol was achieved using a series of HZSM-5 catalysts. The effect of the structure and morphology of ZSM-5 on the conversion of methanol to propylene was studied. The structure and physicochemical properties of the synthesized catalysts were analyzed by multiple characterization techniques. The characterization results revealed that the alumina content rationally modified the acid properties of ZSM-5. When using a ZSM-5 catalyst with a hexagonal single crystal and a Si/Al ratio of 177, the selectivity of propylene reached 39.7% at 480 °C. Furthermore, the formation of methane was reduced. This provides a clue for catalyst design to enable the selective transformation of methanol into propylene. Full article
(This article belongs to the Special Issue Catalytic Conversion of Low Carbon Alkane)
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13 pages, 2810 KiB  
Article
Pd-Bi-Based Catalysts for Selective Oxidation of Glucose into Gluconic Acid: The Role of Local Environment of Nanoparticles in Dependence of Their Composition
by Mariya P. Shcherbakova-Sandu, Andrey A. Saraev, Alexey S. Knyazev and Irina A. Kurzina
Catalysts 2024, 14(1), 66; https://doi.org/10.3390/catal14010066 - 15 Jan 2024
Viewed by 962
Abstract
Palladium–bismuth nanomaterials are used in various chemical applications such detectors, electrodes, and catalysts. Pd-Bi catalysts are attracting widespread interest because these catalysts enable the production of valuable products quickly and efficiently, and are environmentally friendly. However, the composition of the catalyst can have [...] Read more.
Palladium–bismuth nanomaterials are used in various chemical applications such detectors, electrodes, and catalysts. Pd-Bi catalysts are attracting widespread interest because these catalysts enable the production of valuable products quickly and efficiently, and are environmentally friendly. However, the composition of the catalyst can have a significant impact on its catalytic performance. In this work, we identified a correlation between the composition of the catalyst and its efficiency in converting glucose into sodium gluconate. It was found that the conversion decreases with increasing bismuth content. The most active catalyst was the 0.35Bi:Pd sample with a lower bismuth content (glucose conversion of 57%). TEM, SEM, EXAFS, and XANES methods were used to describe, in detail, the surface properties of the xBi:Pd/Al2O3 catalyst samples. The increase in particle size with increasing bismuth content, observed in the TEM micrographs, was associated with the low melting point of bismuth (271 °C). The SEM method showed that palladium and bismuth particles were uniformly distributed over the surface of the support in close proximity to each other, which allowed us to conclude that an alloy of non-stoichiometric composition was formed. The EXAFS and XANES methods established that bismuth was located on the surface of the nanoparticle predominantly in an oxidized state. Full article
(This article belongs to the Section Nanostructured Catalysts)
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10 pages, 8171 KiB  
Article
Hydrochloric Acid Catalyzed Hydrothermal Treatment to Recover Phosphorus from Municipal Sludge
by Kai Liu, Yang Xue, Yawei Zhai, Lisong Zhou and Jian Kang
Catalysts 2024, 14(1), 65; https://doi.org/10.3390/catal14010065 - 15 Jan 2024
Viewed by 971
Abstract
Resource utilization of sludge is critical because traditional sludge treatment methods cause a large amount of nutrient loss. This study investigated the impact of hydrochloric acid quantity, reaction temperature, and time on phosphorus release and migration from municipal sludge during hydrothermal treatment and [...] Read more.
Resource utilization of sludge is critical because traditional sludge treatment methods cause a large amount of nutrient loss. This study investigated the impact of hydrochloric acid quantity, reaction temperature, and time on phosphorus release and migration from municipal sludge during hydrothermal treatment and designed a sludge disposal method for the recovery and utilization of phosphorus resources. We know that hydrochloric acid destroys the complexation of calcium and phosphorus precipitates, leading to the selective transfer of phosphorus to the liquid phase, and that the addition of 1–5% hydrochloric acid corresponds to a phosphorus extraction rate in the range of 0.3–98%. When hydrochloric acid is added, a change in temperature and reaction time has a negligible effect on phosphorus. Phosphorus can be recovered using the liquid product obtained under the optimal hydrothermal reaction conditions (adding 5% HCl at 205 °C for 30 min). After adjusting the pH value and adding the magnesium source, struvite (MgNH4PO4·6H2O) can be precipitated quickly and with high purity. At a cost of USD 27.8/ton of sludge, this method can recover 94% of the phosphorus in the sludge, and the bioavailable phosphorus ratio of the product is 93%, therefore, providing an important alternative to existing phosphorus recovery technologies. Full article
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14 pages, 3652 KiB  
Article
Identification of Aniline-Degrading Bacteria Using Stable Isotope Probing Technology and Prediction of Functional Genes in Aerobic Microcosms
by Baoqin Li, Muhammad Usman Ghani, Weimin Sun, Xiaoxu Sun, Huaqing Liu, Geng Yan, Rui Yang, Ying Huang, Youhua Ren and Benru Song
Catalysts 2024, 14(1), 64; https://doi.org/10.3390/catal14010064 - 15 Jan 2024
Viewed by 1151
Abstract
Aniline, a vital component in various chemical industries, is known to be a hazardous persistent organic pollutant that can cause environmental pollution through its manufacturing, processing, and transportation. In this study, the microcosms were established using sediment with a history of aniline pollution [...] Read more.
Aniline, a vital component in various chemical industries, is known to be a hazardous persistent organic pollutant that can cause environmental pollution through its manufacturing, processing, and transportation. In this study, the microcosms were established using sediment with a history of aniline pollution as an inoculum to analyze the aniline biodegradation under aerobic conditions through stable isotope probing (SIP) and isopycnic density gradient centrifugation technology. During the degradation assay, aniline that was 13C-labeled in all six carbons was utilized to determine the phylogenetic identity of the aniline-degrading bacterial taxa that incorporate 13C into their DNA. The results revealed that aniline was completely degraded in the microcosm after 45 and 69 h respectively. The bacteria affiliated with Acinetobacter (up to 34.6 ± 6.0%), Zoogloea (up to 15.8 ± 2.2%), Comamonas (up to 2.6 ± 0.1%), and Hydrogenophaga (up to 5.1 ± 0.6%) genera, which are known to degrade aniline, were enriched in the heavy fractions (the DNA buoyant density was 1.74 mg L−1) of the 13C-aniline treatments. Moreover, some rarely reported aniline-degrading bacteria, such as Prosthecobacter (up to 16.0 ± 1.6%) and Curvibacter (up to 3.0 ± 1.6%), were found in the DNA-SIP experiment. Gene families affiliated with atd, tdn, and dan were speculated to be key genes for aniline degradation based on the abundance in functional genes and diversity in different treatments as estimated using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States version 2 (PICRUSt2) and the Kyoto Encyclopedia of Genes and Genomes (KEGG). This study revealed the functional bacteria and possible degradation genes for aniline degradation in simulated polluted environments through SIP. These findings suggest that important degrading bacteria for the transformation of aniline and potential degradation pathways may be useful in the effective application of bioremediation technologies to remediate aniline-contaminated sites. Full article
(This article belongs to the Special Issue Microbial Biocatalysis, 2nd Edition)
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12 pages, 6889 KiB  
Article
Unraveling FeOx Nanoparticles Confined on Fibrous Mesoporous Silica Catalyst Construction and CO Catalytic Oxidation Performance
by Guobo Li, Weiwei Feng, Yiwei Luo, Jie Yan, Yining Cai, Yiling Wang, Shule Zhang, Wenming Liu and Honggen Peng
Catalysts 2024, 14(1), 63; https://doi.org/10.3390/catal14010063 - 14 Jan 2024
Viewed by 1058
Abstract
Catalytic oxidation is used to control carbon monoxide (CO) emissions from industrial exhaust. In this study, a mesoporous silica material, KCC-1, was synthesized and used as a carrier with a high specific surface area to confine active component FeOx nanoparticles (NPs), and [...] Read more.
Catalytic oxidation is used to control carbon monoxide (CO) emissions from industrial exhaust. In this study, a mesoporous silica material, KCC-1, was synthesized and used as a carrier with a high specific surface area to confine active component FeOx nanoparticles (NPs), and the CO catalytic oxidation performance of x%Fe@KCC-1 catalysts (x represents the mass loading of Fe) was studied. The experimental results showed that due to its large specific surface area and abundant mesopores, the FeOx NPs were highly dispersed on the surface of the KCC-1 carrier. The particle size of FeOx was very small, resulting in strong interactions between FeOx NPs and KCC-1, which enhanced the catalytic oxidation reaction on the catalyst. The FeOx loading improved the CO adsorption capability of the catalyst, which facilitated the catalytic oxidation of CO, with the 7%Fe@KCC-1 catalyst achieving 100% CO conversion at 160 °C. The CO catalytic removal mechanism was investigated by a combination of in-situ DRIFTS and DFT calculations. This study advances scientific understanding of the application potential of nano-catalysts in important oxidation reactions and provides valuable insights into the development of efficient CO oxidation catalysts. Full article
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28 pages, 8399 KiB  
Article
Green Fabrication of ZnO Nanoparticles and ZnO/rGO Nanocomposites from Algerian Date Syrup Extract: Synthesis, Characterization, and Augmented Photocatalytic Efficiency in Methylene Blue Degradation
by Kamilia Madi, Derradji Chebli, Hakima Ait Youcef, Hichem Tahraoui, Abdallah Bouguettoucha, Mohammed Kebir, Jie Zhang and Abdeltif Amrane
Catalysts 2024, 14(1), 62; https://doi.org/10.3390/catal14010062 - 13 Jan 2024
Cited by 3 | Viewed by 1781
Abstract
This innovative article provides a detailed description of the successful biosynthesis of zinc nanoparticles (ZnO-NPs) using an aqueous extract of Algerian Date Syrup, also known as molasses. A meticulous process was carried out to determine the optimal calcination temperature for ZnO-NPs, a crucial [...] Read more.
This innovative article provides a detailed description of the successful biosynthesis of zinc nanoparticles (ZnO-NPs) using an aqueous extract of Algerian Date Syrup, also known as molasses. A meticulous process was carried out to determine the optimal calcination temperature for ZnO-NPs, a crucial step in the preparation of these nanoparticles. The study was further extended by creating ZnO/rGOx nanocomposites through a hydrothermal method, varying the concentrations of reduced graphene oxide (rGO) at 5%, 10%, and 15%. The characteristics of the nanocomposites were thoroughly explored, encompassing chemical, optical, and morphological aspects, using sophisticated analysis techniques such as scanning electron microscopy (SEM), UV-visible diffuse reflectance spectroscopy (UV DRS), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). These analyses provided an in-depth understanding of the structure and properties of the nanocomposites. The centerpiece of this study is the evaluation of the photocatalytic degradation capacity of ZnO-NPs and ZnO/rGOx nanocomposites. These materials have demonstrated their ability to act as cost-effective and environmentally friendly photocatalysts for wastewater treatment. Experiments on methylene blue degradation under UV irradiation were conducted, yielding impressive results: a degradation efficiency of 86.6% was achieved in 140 min using 1 g/L of ZnO-NPs, and this rate reached 100% with the ZnO/rGO catalyst in the same time frame, highlighting its superiority as a photocatalyst. Furthermore, this study examined the variables affecting the photocatalysis experiment, including the solution’s pH and the amount of catalyst. The results revealed that the ZnO/rGO photocatalyst reached its optimal efficiency under neutral pH conditions and at a concentration of 1 g/L, providing crucial information for practical use of these materials. This enriched article highlights the promising potential of ZnO-NPs and ZnO/rGOx nanocomposites as efficient photocatalysts for methylene blue degradation, paving the way for significant environmental applications in wastewater treatment. Full article
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