Hydrogen Fuel Cell Vehicles: Opportunities and Challenges

Round 1

Reviewer 1 Report

This paper reviews the hydrogen fuel cell vehicles from views of "Opportunities and Challenges", which has potential application value in engineering. In order to meet the requirements of high-quality publication of the journal, it is recommended to consider the following suggestions.

1) It is best to have the best performance data in the field covered by this review in the abstract.

2) Does the format of meet the requirements of the journal? Why no Line No.?

3) When discussing hydrogen energy (in Section 1.3. Current status of hydrogen energy), it is recommended to cite the following papers.

   (a) A systematic review of machine learning methods applied to fuel cells in performance evaluation, durability prediction, and application monitoring. INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, 2023, 48 (13)

:5197-5228,DOI:10.1016/j.ijhydene.2022.10.261

   (b) An operationally flexible fuel cell based on quaternary ammonium-biphosphate ion pairs. Nature Energy, 2016, 1(9):16120.

4) A review paper requires high quality comparative Tables and one's own statistical Figures.

There is no data in Table 1, Why?

5) Please check the format, such as Table 5.

6) Please confirm the copyright issues of all Figures.

7) The discussion needs to be included into a separate section.

8) The logic of Section 9 needs to be clearer.

Author Response

Dear SIR/Mad;

Please see the uploaded file as requested

Regards

Author Response File: Author Response.docx

Reviewer 2 Report

In this article, the authors have explained the current and future prospects of HFCVs. This article highlights the importance of HFC vehicle existence in the market of already existing combustion engine-based vehicles. HFCV used the green fuel known as H2 which with a chemical reaction generates electrical energy without eliminating any harmful gas. The article shows the growing market of HFCVs through some companies with a positive impact. The conclusion and future directions also highlight the importance of HFCVs. Therefore, I recommend the manuscript for publication with some required explanations:

1. It will be better to explain the kinetics and thermodynamics of the reactions involved with electrochemical potential.

2. Why photoelectrochemical H2 production is facing challenges? more explanation is required.

3. Please explain what makes the cost of HFCVs higher.

4. Why there are limited manufacturing companies for HFCVs? This arises the question of the sustainability of these vehicles.

5. Where does this vehicle exist in front of battery-based vehicles in terms of efficiency?

Author Response

Dear Sir/Mad;

Please see the uploaded file as requested 

Regards 

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Can be accepted