Determination of Activation Energy on Hydrogen Evolution Reaction for Nickel-Based Porous Electrodes during Alkaline Electrolysis

Round 1

Reviewer 1 Report

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Author Response

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Reviewer 2 Report

The present work evaluated the activation energy at different cathodic overpotentials and the stability after 1000 cycles of operation of Nickel-based, NiCr-m, and NiCr-p porous electrodes, which were sintered with a heating rate of 25°C up to a temperature of 1000°C and 1200°C during 60 minutes. The electrodes were prepared metallographically to observe their morphology. Later potentiodynamic tests were carried out at different temperatures. Cyclic voltammetry tests were performed to determine the catalytic activity and stability of the electrodes, finding that the NiCr-p electrode corresponds to an electrode obtained made from pre-alloyed NiCr powders and sintered at 1200°C shows better performance and higher stability attributed to a homogeneous Cr distribution in Nickel matrix. This paper is very interesting and could be published aftor minior revision.

(1) Graphical Abstract should be re-organized to better express the novelty of this work.

(2）Conclusion, Should be delete out all introductory rephrases and unnecessary expressions.

（3）The format of the manuscript should be carefully checked and revised.（4）The English language needs significant attention as several sentences are not quite clear.

（5）Some paper should be cited to enrich the background such as "Revisited electrochemical gas evolution reactions from the perspective of gas bubbles" "Defect-driven selective oxidation of MoS2 nanosheets with photothermal effect for Photo-Catalytic hydrogen evolution reaction"Tailoring activation sites of metastable distorted 1T′-phase MoS2 by Ni doping for enhanced hydrogen evolution"

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

This paper contains novel findings on the electrocatalytic hydrogen evolution activity of porous Ni-Cr electrodes. The manuscript is well-constructed. The subject of this study is appropriate for publication in Catalysts. Several revisions described below are recommended prior to acceptance for publication. 

 

(1) Abstract: Descriprion on the background is quite long. The abstract can be made more concise.

 

(2) Explanation on the relationship between distribution state of Cr (solid solution formation, oxide formation, etc) and catalytic activity seems still vague. The authors should distinctly comment on the effect of uniform distribution of Cr on the catalytic activity. If there are surface analysis results (for example, XPS), they should be added; the previous results on the surface oxide layer formation has been referred in the text (line 282).

 

(3) Figure 5 and 6: Cr was found in segregated form in the case of NiCr-m (Figure 5c), but ctystalline Cr was not found by XRD (Figure 6). Explanation on this imcompatibility is necessary.

 

(4) Figure 5d): Although the classification of Cr (green) and Ni (red) was shown in the sentences (line 128), but what yellow region represents is not shown.

 

(5) Table 2: the column of R2 has not been completely filled (two parts contain the notation "data"). Which variables are correlated by the R2?

 

(6) Both notations "Ni-based" and "based-Ni" are mixed. Please check.

 

(7) The difinitions of the symbols "Jp" and "Jη" have not been clearly specified.

 

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

All my comments have been addressed at acceptable level, thus I would like to recommend publication of the manuscript in the current form.

Reviewer 2 Report

This paper could be published now

Reviewer 3 Report

This manuscript has been satisfactorily improved and can be accepted for publication.