Catalytic Properties of the Spinel-Like CuxMn3−xO4 Copper Manganese Oxides—An Overview
Round 1
Reviewer 1 Report
This is an excellently prepared manuscript devoted to the actual problem of using spinel–like CuxMn3–xO4 Copper Manganese Oxidesin catalysis. The authors briefly outlined the general data of the synthesis strategy and the structural parameters of the main classes of spinels based on copper oxide. The section devoted to the catalytic applications of the object of study was described very extensively. Data on catalytic activity in the context of various types of reactions were presented in an accessible and understandable form. As a minor remark,
1. Authors should rework the introduction section more carefully. It is necessary to demonstrate in more detail the relevance of this review and its difference from previously published works.
2. It is also necessary to add a conclusion section with the main conclusions of the review and be sure to outline the prospects for further use of spinel–like CuxMn3–xO4 copper manganese oxides in materials science and catalysis in particular.
Author Response
1., This is an excellently prepared manuscript devoted to the actual problem of using spinel–like CuxMn3–xO4 Copper Manganese Oxides in catalysis. The authors briefly outlined the general data of the synthesis strategy and the structural parameters of the main classes of spinels based on copper oxide. The section devoted to the catalytic applications of the object of study was described very extensively. Data on catalytic activity in the context of various types of reactions were presented in an accessible and understandable form. As a minor remark,
1., Authors should rework the introduction section more carefully. It is necessary to demonstrate in more detail the relevance of this review and its difference from previously published works.
The introduction has been rewritten to show the focus of this study, which is different from other studies, and demonstrate the relevance of the topic.
2. It is also necessary to add a conclusion section with the main conclusions of the review and be sure to outline the prospects for further use of spinel like CuxMn3–xO4 copper manganese oxides in materials science and catalysis in particular.
A conclusion section has been added to show the main conclusions and future perspectives.
Reviewer 2 Report
The manuscript systematically reviews the preparation method and their effects on the composition, properties, and catalytic properties of various spinel-like copper manganese oxides. After minor revision to address the comments listed below, this manuscript can be taken into consideration for acceptance.
Comment 1. In Chapter 2, authors discussed different preparation routes of spinel-like copper manganese oxides. A precise Table (like the style of Table 4) is highly suggested to add so that the audience can directly locate specific information from this Chapter.
Comment 2. In Chapter 4, authors reviewed four catalytic applications of spinel-like copper manganese oxides. As described in Figures 4 &5, spinel-like copper manganese oxides generally follow a redox mechanism. In fact, redox mechanism is complex, and it may involve different parallel pathways, including Eley-Rideal mechanism / Mars-van-Krevelen mechanism / Dual site Langmuir-Hinshelwood mechanism. Discussion of these different pathways listed above are recommended to include and discuss in details as well.
Comment 3. A clear shortage of this manuscript is that this paper ends abruptly and obviously the Conclusion Chapter is missing. Authors should put forward some perspectives regarding the leading-edge research topics of the spinel-like copper manganese oxides. In addition, a brief introduction of operando characterization techniques to interpret the mechanistic understanding of catalytic spinel-like copper manganese oxides are highly recommended to be added as well.
Author Response
First of all, we would like to express our thanks for the careful work of the reviewer. All of their suggestion has been inserted into the text.
The answers to the requests are given below.
The manuscript systematically reviews the preparation method and their effects on the composition, properties, and catalytic properties of various spinel-like copper manganese oxides. After minor revision to address the comments listed below, this manuscript can be taken into consideration for acceptance.
Comment 1. In Chapter 2, authors discussed different preparation routes of spinel-like copper manganese oxides. A precise Table (like the style of Table 4) is highly suggested to add so that the audience can directly locate specific information from this Chapter.
We have added two tables about the synthetic routes and conditions (solid phase and solution phase methods). The procedures of synthesis are arranged in each table according to the composition of the products.
Comment 2. In Chapter 4, authors reviewed four catalytic applications of spinel-like copper manganese oxides. As described in Figures 4 &5, spinel-like copper manganese oxides generally follow a redox mechanism. In fact, redox mechanism is complex, and it may involve different parallel pathways, including Eley-Rideal mechanism / Mars-van-Krevelen mechanism / Dual site Langmuir-Hinshelwood mechanism. Discussion of these different pathways listed above are recommended to include and discuss in details as well.
A discussion about the possible mechanisms has been added.
Comment 3. A clear shortage of this manuscript is that this paper ends abruptly and obviously the Conclusion Chapter is missing. Authors should put forward some perspectives regarding the leading-edge research topics of the spinel-like copper manganese oxides. In addition, a brief introduction of operando characterization techniques to interpret the mechanistic understanding of catalytic spinel-like copper manganese oxides are highly recommended to be added as well.
A conclusion section has been added to show the main conclusions and future perspectives. A section is also added about the main investigation methods to study the phase relations/transformations during the catalytic cycles and following the catalytic reactions.
Reviewer 3 Report
Novelty of the Work:
A new data about, the Catalytic properties of the spinel–like CuXMn3–XO4 copper manganese oxides were obtained.
Significance of the Work:
The authors show a new data for the preparation methods and their effects on the composition, properties, and catalytic properties of various CuxMn3–xO4 catalysts with various Cu/Mn ratios. The main summarized catalytic reactions are the oxidation of carbon monoxide, nitrogen oxide, and hydrogen sulfide and the oxi- dative removal of organic solvents like benzene, toluene, and xylene from the air. Some industrially important reactions (steam reforming of methanol or synthesis gas) and the manufacture of organic chemicals (methyl formate, propylene oxide, and benzyl alcohol) catalyzed by CuxMn3–xO4 spinels, are also reviewed.
Other Specific Comments:
Introduction - Despite the extensive references, the authors have to do more relevant discussion about different preparation methods of CuxMn3–xO4 catalysts.
Conclusions - The authors should give an outlook on future research work.
Author Response
First of all, we would like to express our thanks for the careful work of the reviewer. All of their suggestion has been inserted into the text.
The answers to the requests are given below.
Novelty of the Work:
A new data about, the Catalytic properties of the spinel–like CuXMn3–XO4 copper manganese oxides were obtained.
Significance of the Work:
The authors show a new data for the preparation methods and their effects on the composition, properties, and catalytic properties of various CuxMn3–xO4 catalysts with various Cu/Mn ratios. The main summarized catalytic reactions are the oxidation of carbon monoxide, nitrogen oxide, and hydrogen sulfide and the oxi- dative removal of organic solvents like benzene, toluene, and xylene from the air. Some industrially important reactions (steam reforming of methanol or synthesis gas) and the manufacture of organic chemicals (methyl formate, propylene oxide, and benzyl alcohol) catalyzed by CuxMn3–xO4 spinels, are also reviewed.
Other Specific Comments:
Introduction - Despite the extensive references, the authors have to do more relevant discussion about different preparation methods of CuxMn3–xO4 catalysts.
The discussions of the preparation methods have been added with some conclusive paragraphs and two tables about the synthetic conditions.
Conclusions - The authors should give an outlook on future research work.
A conclusion section has been added to show the main conclusions and future perspectives
Reviewer 4 Report
The authors reviewed the different methods to Cu-Mn binary oxides and discussed their possible effects on the composition, properties and catalytic properties. Indeed, the proposed subject was of great importance and deserved to be deeply studied. However, the associated descriptions about the possible conclusion and the exciting outlook in the certain research fields were still missing in the draft. I will consider the manuscript acceptable after a major revision.
1. All the schemes and figures displayed in the manuscript should be high-resolution.
2. The simple summary on the preparation methods was far from satisfactory to the readers. Some helpful discussion should be added in the section of Introduction and Conclusion.
3. The language should be further polished, including the spell and grammar.
Author Response
First of all, we would like to express our thanks for the careful work of the reviewer. All of their suggestion has been inserted into the text.
The answers to the requests are given below.
The authors reviewed the different methods to Cu-Mn binary oxides and discussed their possible effects on the composition, properties and catalytic properties. Indeed, the proposed subject was of great importance and deserved to be deeply studied. However, the associated descriptions about the possible conclusion and the exciting outlook in the certain research fields were still missing in the draft. I will consider the manuscript acceptable after a major revision.
- All the schemes and figures displayed in the manuscript should be high-resolution.
The figures have been improved according to our possibilities.
- The simple summary on the preparation methods was far from satisfactory to the readers. Some helpful discussion should be added in the section of Introduction and Conclusion.
The discussions of the preparation methods have been added with some conclusive paragraphs and two tables about the synthetic conditions.
- The language should be further polished, including the spell and grammar.
The language of the text has been checked and revised at many points.
Round 2
Reviewer 4 Report
The authors have addressed all the concerns. I would like to suggest it acceptable in present form.
