One-Step Preparation of Nitrogen-Doped Platinum-Based Catalysts for Electrocatalytic Oxidation of Ethanol

Round 1

Reviewer 1 Report

This paper reports the study of performed a systematic study to Pt/nitrogen-doped reduced graphene oxide (N-RGO) catalysts were prepared by one-step 10 microwave-assisted ethylene glycol reduction using N-methyl-2-pyrrolidone (NMP) as the nitrogen 11 source. Nitrogen doping in GO and the deposition of highly dispersed platinum nanoparticles were 12 completed at the same time. The effect of adding NMP on the microstructure and electrocatalytic 13 performance of Pt/N-RGO catalysts were studied. The results show Pt/N-RGO catalysts have better 14 particle size distribution and electrocatalytic performance compared with undoped catalyst. When 15 the ratio of GO to NMP reaches 1:200, the peak current density of the catalyst is about 3 times that 16 of the non-nitrogen-doped Pt/RGO catalyst, which indicates that the electrocatalytic performance of 17 the catalyst is the best. Therefore, the development of one-step synthesis of Pt/N-RGO catalysts have 18 a broad application prospect in direct ethanol fuel cell (DEFCs). The experimental results are interesting and informative, but some data were not well presented. Details are listed below.

1) The Pt/nitrogen-doped reduced graphene oxide (N-RGO) catalysts of should be shown cyclic voltammograms (CVs), specific and mass activity for ethanol oxidation reactions.
2) The authors performed a stability test. However, TEM data must be added before and after the reaction because the data in Figure 9 is insufficient.
3) The authors did not compare the commonly used Pt/C catalytic activity. A comparison of Pt/C should be added to prove that the synthesized catalyst is highly active.
4) In order to compare the surface area of the synthesized particles, the calculation of electrochemical active surface area (ECSA) is necessary. Comparison value of calculation method and data calculated surface area should be added.

Author Response

Response to the comments by the reviewer:

Manuscript ID: catalysts-1408077

Title: One-step preparation of Nitrogen-doped Platinum-based Catalysts for Electrocatalytic Oxidation of Ethanol

Dear referees：

Thank you for your useful comments and suggestions on our manuscript. We have modified the manuscript accordingly, and detailed corrections are listed in the manuscript.

 

Reviewer #1:

• The Pt/nitrogen-doped reduced graphene oxide (N-RGO) catalysts of should be shown cyclic voltammograms (CVs), specific and mass activity for ethanol oxidation reactions.

Reply: Thank you for your good suggestions. We added the specific activity and mass activity of the samples and nalyzed the results, as shown in Figure 7 (b) in the manuscript.

 

• The authors performed a stability test. However, TEM data must be added before and after the reaction because the data in Figure 9 is insufficient.

Reply: Thank you very much for your advice. However, the amount of catalyst samples left on the electrode surface after electrochemical test is very small, and it is difficult to perform secondary characterization. We will find better measures to improve this problem in future studies.

 

• The authors did not compare the commonly used Pt/C catalytic activity. A comparison of Pt/C should be added to prove that the synthesized catalyst is highly active.

Reply: Thank you for your good suggestions. Pt/C catalysts have been added to the manuscript, as shown in Electrochemical curves.

 

• In order to compare the surface area of the synthesized particles, the calculation of electrochemical active surface area (ECSA) is necessary. Comparison value of calculation method and data calculated surface area should be added.

Reply: Thank you for your good suggestions. We added electrochemical active surface area of the samples, as shown in Figure 6.

 

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Developing environment-friendly, renewable new energy has become increasingly appealing since. It provides a promising resolve for current energy exhaustion and environmental pollution. In this regard, the preparation of high-performance catalysts use in the fuel cell is relevant. Nitrogen-doped reduced graphene oxide platinum-based catalysts are promising for fuel cells. I think the article can be published after minor corrections. 
1. I think the title "synthesis" should replace to the  "preparation"; 
2. need to provide a VA curves measurement scheme; 
It is necessary to give the comparative characteristics for Pt/Nx-GO, Pt/GO and commercially available Pt/С catalysts samples$
3. what is the durability of Pt/Nx-GO catalysts?
4. сyclic voltammograms curves must be brought without points, otherwise, they are difficult to understand;
5. in table 1 and 2 catalyst samples should be designated differently, not by numbers;
6. in "2.1. Preparation of Pt / Nx-G catalysts", probably meant "Pt / Nx-GO catalysts".

Author Response

Response to the comments by the reviewer:

Manuscript ID: catalysts-1408077

Title: One-step preparation of Nitrogen-doped Platinum-based Catalysts for Electrocatalytic Oxidation of Ethanol

Dear referees：

Thank you for your useful comments and suggestions on our manuscript. We have modified the manuscript accordingly, and detailed corrections are listed in the manuscript.

 

Reviewer #2:

• I think the title "synthesis" should replace to the "preparation".

Reply: Thank you for your good suggestions. We have replaced the word in the manuscript.

 

• Need to provide a VA curves measurement scheme; It is necessary to give the comparative characteristics for Pt/Nx-GO, Pt/GO and commercially available Pt/С catalysts samples

Reply: Thank you for your good suggestions. Comparison characteristics for Pt/Nx-GO, Pt/GO and commercially available Pt/С catalysts samples have been added to the manuscript.

 

• What is the durability of Pt/Nx-GO catalysts?

Reply: According to Figture 10, Pt/Nx-GO catalysts showed better durability than the catalysts without N doping. The stability of the catalysts doped with N is better than that of Pt/G and commercial Pt/C(JM) catalyst. This is due to the fact that the N-containing functional groups on the surface of graphene support can anchor Pt nanoparticles, inhibit the migration and aggregation of Pt nanoparticles in multiple cycles, and improve the stability of the catalyst.

 

• Cyclic voltammograms curves must be brought without points, otherwise, they are difficult to understand;

Reply: Thank you for your good suggestions. We have changed and marked in the manuscript.

 

• In table 1 and 2 catalyst samples should be designated differently, not by numbers;

Reply: Thank you for your good suggestions. We have changed and marked in the manuscript.

 

(6) 2.1. Preparation of “Pt / Nx-G catalysts”, probably meant "Pt / Nx-GO catalysts".

Reply: We appreciate the reviewer for pointing out this editing error. “Pt/Nx-G catalysts” meant "Pt / Nx-GO catalysts". We have changed and marked in the manuscript.

 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

This thesis has been well edited. I hope this paper will be published.