Durability of Commercial Catalysts within Relevant Stress Testing Protocols
, Ilya Pankov 2, Sergey Belenov 1,* and Anastasia Alekseenko 1Round 1
Reviewer 1 Report
This is an interesting paper focused on studying the influence of the conditions of a new stress testing protocol on the degradation of electrocatalysts, particularly the HiSPEC3000 and HiSPEC4000 samples. The results of their comparison can be helpful in asessing the behavior of these catalysts within various stress testing protocols. Here are some comments I have:
1. In the Abstract and in the Conclusions, I suggest the authors to change the writing style slightly, to make more emphasis on what their contribution actually was. I suggest using the first person, using phrases like: "In this work, we found..."", "We did..." or "We conclude that..." in the Abstract and Conclusions because otherwise, I believe the authors contributions gets diluted among the literature review. It's not quite clear what the paper will be about until you reach section 2.1
2. Graphs on Figure 1 should be enlarged. I even would suggest that each graph should be presented as a separate Figure so it can be properly visualized.
3. Table 1 caption should be in the following page, next to the actual table. Also I would change the beginning of the caption from "The electrochemical activity of..." to "Electrochemical activity of...". More about the use of "The" in phrases can be found here: https://grammar.collinsdictionary.com/easy-learning/when-do-you-use-the-in-english
I suggest to also remove the article "The" at the beginning of the caption in Figures 2-8.
Apart from those comments, I believe the paper is robust, well written and the research design is appropriate. I recommend publication after the authors address my comments.
Best regards
Author Response
The authors express their deep appreciation to the reviewers for their careful review of the manuscript and the comments made.
- In the Abstract and in the Conclusions, I suggest the authors to change the writing style slightly, to make more emphasis on what their contribution actually was. I suggest using the first person, using phrases like: "In this work, we found..."", "We did..." or "We conclude that..." in the Abstract and Conclusions because otherwise, I believe the authors contributions gets diluted among the literature review. It's not quite clear what the paper will be about until you reach section 2.1
- The authors agree with the comment made. The corresponding corrections have been made to the manuscript.
- Graphs on Figure 1 should be enlarged. I even would suggest that each graph should be presented as a separate Figure so it can be properly visualized.
- The authors agree with the comment made. Figure 1 has been corrected.
- Table 1 caption should be in the following page, next to the actual table. Also I would change the beginning of the caption from "The electrochemical activity of..." to "Electrochemical activity of...". More about the use of "The" in phrases can be found here: https://grammar.collinsdictionary.com/easy-learning/when-do-you-use-the-in-english
- The authors agree with the comment made. The corresponding corrections have been made to the manuscript, including Table 1.
I suggest to also remove the article "The" at the beginning of the caption in Figures 2-8.
- The corresponding corrections have been made to the manuscript, including Figures 2–8.
Reviewer 2 Report
The manuscript presents the results of the durability of the commercial Pt/C with JM20 and JM40 in different gas purged. By comparing the electrochemically active surface area, the activity and size of Pt nanoparticles before and after ADT in ORR, two different mechanism of the degradation for the catalyst were proposed. The work was also well organized and written. Just two things need to be paid attention.
1．The authors conclude that for a different nature of the platinum nanoparticles’ distribution in argon and oxygen for the JM20 can be attributed to the predominant oxidation of the carbon support. Why the difference is not shown for the JM40.
2. The format of the journal name is not uniform. Some are abbreviations, whereas some are full names.
well written
Author Response
The authors express their deep appreciation to the reviewers for their careful review of the manuscript and the comments made.
1．The authors conclude that for a different nature of the platinum nanoparticles’ distribution in argon and oxygen for the JM20 can be attributed to the predominant oxidation of the carbon support. Why the difference is not shown for the JM40.
- Differences in the distribution nature of platinum nanoparticles before and after the durability testing in argon and oxygen are shown in Figure 8b and Figure 6, however, they are less pronounced compared to JM20. Therefore, the text of the article states “It is not excluded that a similar degradation mechanism occurs for the JM40 sample after ST-O2, although it is less pronounced and the change in the nature of the NPs’ distribution over the surface of the carbon support in this case is well explained by the agglomeration of NPs.”
- The format of the journal name is not uniform. Some are abbreviations, whereas some are full names.
- The links were designed using automated programs at the request of the journal.
Reviewer 3 Report
This manuscript reported the durability of commercial catalysts within relevant stress testing protocols, and the obtained results were of interests to researchers of the related nanocatalysts and electrochemistry. I recommend it for acceptance after minor revision, as follows:
Q1. It is necessary for authors to demonstrate the scientific meaning and novelties of this manuscript in the Introduction section.
Q2. The authors need to discuss the textural parameters of commercial JM20 and JM40 in the basis of the N2 adsorption-desorption isotherms, such as specific surface areas and pore distributions.
Q3. Figure 1 and 3 should be modified.
Minor editing of English language required
Author Response
The authors express their deep appreciation to the reviewers for their careful review of the manuscript and the comments made.
Q1. It is necessary for authors to demonstrate the scientific meaning and novelties of this manuscript in the Introduction section.
The introduction indicates a substantial number of the accelerated durability tests used, as well as the significance of understanding the features of each of these methods, the catalyst’s degradation mechanisms, and the correct selection of a method to assess the durability of the material. Therefore, comparing the features of different ADT methods using standard commercial materials is fundamentally important for understanding the differences in mechanisms of the catalyst’s degradation depending on ADT conditions.
Q2. The authors need to discuss the textural parameters of commercial JM20 and JM40 in the basis of the N2 adsorption-desorption isotherms, such as specific surface areas and pore distributions.
According to the BET study conducted, the commercial JM20 and JM40 materials have been established to exhibit the area of 185 and 146 m2/g, respectively (Figure 1), the pore volume being 0.278 and 0.210 cm³/g, respectively. All this testifies in favor of the fact that platinum nanoparticles close pores of the carbon support and reduce its area (the area of the Vulcan XC-27 support, according to the measurements performed, is 270 m2/g). Notably, with an increase in the platinum loading from 20 to 40, the area decreases by 39 m2/g. It is also noteworthy that the JM20 and JM40 materials exhibit no differences in the nature of the pore size distribution (Figure 2), i. e., with an increase in the platinum loading, all pores, except for the largest ones of more than 6 nm in size, are uniformly closed.
Q3. Figure 1 and 3 should be modified.
The authors agree with the comment made. Figures 1 and 3 have been modified.
Author Response File: 
Author Response.pdf
