Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This manuscript reviews mainstream hydrogen production techniques, with a focus on steam methane reforming (SMR) and water electrolysis. SMR is currently mainstream (95% of the world), but relies on fossil fuels and has high carbon emissions (about 10.9 gCO₂/gH₂). Water electrolysis (especially alkaline electrolytic cell AWE, proton exchange membrane PEM, and anion exchange membrane AEM) is regarded as a green alternative. It uses renewable energy to decompose water (H₂ accounts for 11.11% of the water mass) and can achieve near-zero emissions. The manuscript system compares the technical principles, processes (including flow charts and reaction formulas) and carbon emission data of various technologies, emphasizing the sustainable potential of combining electrolysis with renewable energy. However, there are still shortcomings in the manuscript. For example, some charts (such as SMR flow charts) are missing, emerging electrolytic technologies (such as solid oxides) are less discussed, and there is no in-depth analysis of the costs and economic bottlenecks of each technology.   

The content of the manuscript is within the scope of the journal and can be of broad interest to readers. However, in terms of specific content, there is still room for improvement. Therefore, I decided to give the decision of minor revision. It is recommended that the author properly absorb the reviewers' comments and make corresponding improvements and enhancements.

1. For the keywords, 'steam methane reforming', 'membrane studies', 'operating parameters', and 'water electrolysis' should be added to attract a broader readership.

2. Page 2, 'Today, worldwide energy consumption has gradually increased due to the growth in population and standard of living. Hydrogen is one of the most promising clean and sustainable energy carriers...'
    I think the relationship between renewable energy and green hydrogen production does not seem to be well clarified in this Introduction. I suggest adding a description of this part. 
    For example, renewable energy sources, such as wind, solar and wave power, as well as other natural resources, are widely recognized as effective alternatives to fossil fuels. However, due to inherent limitations in the intermittent and fluctuating nature, their stability in energy supply and large-scale promotion have been limited. Hydrogen energy holds significant potential in the clean energy transition and is an effective pathway for achieving large-scale deep decarbonization. Electrolysis of water for green hydrogen production is not only one of the ways to obtain hydrogen resources, but also contributes to addressing the intermittency and variability of renewable energy sources (10.3390/polym16192840).

3. The data source is unclear. Many key data are not cited (such as "96% of global hydrogen energy relies on fossil fuels" and "PEM electrolyzer expected production capacity in 2030"). The data source agency (IEA, IRENA, etc.) and the original report number need to be added to enhance the credibility of the data.

4. Some concepts are expressed too absolutely. The conclusion contains an absolute statement that "water electrolysis is the only way to achieve carbon neutrality" (paragraph 14 of the original text). It is recommended to correct it to "one of the key ways" and add a comparative discussion of other low-carbon hydrogen production technologies (such as biomass gasification).

5. The analysis of electrolyzer life and health management is weak. When discussing the technical bottleneck of electrolyzers (Section 3.3), the manuscript only generally describes the "life and efficiency degradation problem", lacks quantitative analysis of the degradation mechanism of proton exchange membrane (PEM) electrolyzers under dynamic conditions, and especially does not touch on the health status assessment (SOH) method, resulting in a lack of basis for operation and maintenance strategy recommendations. 
    Hence, it is recommended to supplement the degradation correlation study of PEM electrolyzers/fuel cells, where the degradation mechanism of the anode Ir catalyst of the PEM electrolyzer (such as IrO₂ dissolution) and the degradation of the cathode Pt of the PEM fuel cell have electrochemical similarities, such as the polarization loss decomposition model in Figure 3 of International Journal of Hydrogen Energy 157 (2025): 150162.

6. The comparison of electrolyzer technologies is superficial. Table 1 should be supplemented with a comparison of the quantitative indicators of the three electrolysis technologies: current density (kA/m²), energy consumption (kWh/kg H₂), and platinum group metal usage (g/kW). In particular, the breakthrough of the AEM electrolyzer in precious metal reduction should be emphasized.

7. The analysis of hydrogen production bottlenecks is weak. The by-product hydrogen of chlor-alkali production should be analyzed in depth in terms of the mercury pollution risk of the mercury/membrane process and the bottleneck of ion membrane localization. In addition, it is necessary for the author to further supplement the technical economic analysis (TEA) data to compare the membrane/mercury process costs (USD/kg H₂).

8. The coordinated optimization of hydrogen production and use systems is missing. In the system integration section, Section 5.2 of the manuscript only focuses on the hydrogen production link, and does not discuss the sensitivity of green hydrogen downstream applications (such as fuel cells) to hydrogen quality, ignoring the chain effect of "hydrogen production purity → fuel cell life → full life cycle cost".
    It is recommended to expand the perspective of hydrogen production and hydrogen use coordinated design, and add "hydrogen quality-terminal equipment life coupling mechanism" analysis in Section 5.2. In addition, under dynamic hydrogen production load, the mechanical stress failure mode of the electrolyzer membrane electrode is highly consistent with that of the on-board fuel cell. The accelerated aging experimental data of 'health state estimation and long-term durability prediction for vehicular PEM fuel cell stacks under dynamic operational conditions' can be referred to, and the "multi-physics field coupling SOH evaluation framework" proposed in the above study can be cited to quantify the impact of renewable energy fluctuations on the life of the electrolyzer.

Author Response

Reviewer 1

 

1. For the keywords, 'steam methane reforming', 'membrane studies', 'operating parameters', and 'water electrolysis' should be added to attract a broader readership.

 

Keywords: Hydrogen production technologies; sustainable hydrogen production; steam methane reforming; water electrolysis; membrane studies; greenhouse gas emissions.

 

2. Electrolysis of water for green hydrogen production is not only one of the ways to obtain hydrogen resources, but also contributes to addressing the intermittency and variability of renewable energy sources (10.3390/polym16192840).

 

Renewable energy sources such as wind, solar, and wave power, along with other natural resources, are increasingly gaining favor among scientists worldwide and are widely recognized as effective alternatives to fossil fuels. Hydrogen in energy transition: A review. However, due to the limitations inherent in its intermittent and fluctuating nature, its stability in energy supply and large-scale promotion have been limited. Hydrogen energy has enormous potential in the transition to clean energy and is an effective way to achieve large-scale decarbonization in sectors such as transportation, industry, and construction. The use of water electrolysis to produce hydrogen is not only one of the ways to obtain energy from hydrogen, but also helps to solve the intermittency and variability of renewable energies.Advances in the Application of Sulfonated Poly(Ether Ether Ketone) (SPEEK) and Its Organic Composite Membranes for Proton Exchange Membrane Fuel Cells (PEMFCs).

 

3. The data source is unclear. Many key data are not cited (such as "96% of global hydrogen energy relies on fossil fuels" and "PEM electrolyzer expected production capacity in 2030"). The data source agency (IEA, IRENA, etc.) and the original report number need to be added to enhance the credibility of the data.

 

Proton exchange membrane water electrolysers (PEMWE) are expected to contribute significantly to the green hydrogen market. However, the market penetration of PEMWE is negligible, accounting for less than one gigawatt of global capacity [1]. Proton exchange membrane (PEMWE) electrolysis, as one of the most mature methods for green hydrogen production, has expanded rapidly, and global installed electrolyzer capacity is expected to reach 170–365 GW by 2030 [28]. In order to achieve zero emissions by 2050, proton exchange membrane water electrolyzer (PEMWE) capacity should reach 1130 GW by 2050 [3]

 

 

 

 

 

 

 

 

 

 

4. one of the key ways" and add a comparative discussion of other low-carbon hydrogen production technologies (such as biomass gasification).

 

Hydrogen production from biomass gasification has not been included. However, production from photocatalysis and electrophotocatalysis has been included.

 

Production of hydrogen by splitting water through photocatalysis.

Photocatalysis is a promising technology for hydrogen production, as it enables the conversion of solar energy into chemical energy through radiation-induced processes [4]. Photocatalytic water splitting (PWS) involves the dissociation of water into hydrogen (H₂) and oxygen (O₂) using more abundant renewable resources such as water and sunlight. It is considered a very promising technology due to its environmentally friendly nature and zero global warming potential [5]. Photocatalysis involves exciting semiconductor catalysts with adequate exposure to light, which generates electrons and holes that can then participate in reduction and oxidation reactions such as water splitting, offering a sustainable alternative to conventional methods [6] . It is considered an important strategy for promoting clean energy and overcoming global environmental challenges. As a result, numerous photocatalysts have been developed in recent years [7].  The photocatalytic reaction of water splitting comprises two half-reactions: the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER), whose combination constitutes the overall reaction of water (OWR)[8] .These redox reactions are described by the following equations (1), (2), and (3)

              Photo oxidation   :

              Photo reduction   : 

             whose combination of equations (1) and (2) constitutes the overall reaction of water

             splitting.

              Overall reaction :

Titanium dioxide (TiO₂) has been the most common photocatalyst used to produce hydrogen, due to its stability, corrosion resistance, cleanliness (nonpolluting), availability in nature, and low cost [9].  While significant progress has been made in photocatalytic water splitting for hydrogen production, current challenges include efficiency, scalability, and material cost. New approaches to catalyst design, reactor engineering, and systems integration continue to drive the field toward industrial-scale green hydrogen production [10]. Recent studies have reported that nanostructured shell-core catalysts represent a significant evolution over traditional shell-core nanostructures, offering improved catalytic activity, structural stability, and multifunctionality for water splitting applications [11]. Developing yolk-shell catalysts with low-cost and earth-abundant materials is critical to reduce overall production costs and improve sustainability [12]. In this context, photocatalytic technology that uses semiconductors for solar-driven H₂ production has generated significant interest [13] . The development of yolk-shell catalysts using low-cost, abundant materials is essential for reducing overall production costs and improving sustainability.

 

Photoelectrocatalytic hydrogen production by water splitting

Photoelectrocatalytic (PEC) hydrogen production from water is a promising sustainable technology that uses the principles of photocatalysis and electrocatalysis to break water down into hydrogen and oxygen at ambient temperature and pressure without greenhouse gas emissions [14] . Water dissociation using PEC involves semiconductor photoelectrodes immersed in aqueous electrolytes. Sunlight excites semiconductors, creating electron-hole pairs that drive water dissociation reactions: oxidation of water at the anode, generating oxygen, and reduction of protons at the cathode, producing hydrogen [15] . These processes facilitate the following redox reactions:

             At the anode:

            At the cathode:  

The photoelectrochemical (PEC) splitting of water provides a “green” approach to hydrogen production. However, the design and manufacture of high-efficiency catalysts are the bottleneck for PEC water splitting due to the thermodynamic and kinetic challenges involved [16] . This technology shows great promise for the generation of clean hydrogen, but requires further research into materials science, reaction mechanisms, and engineering solutions to overcome current limitations and effectively scale up production [17]. Photoelectrochemical cells for water splitting are characterized by their division into two reaction compartments separated by an ion exchange membrane. The implementation of a membrane is a simple and crucial strategy for ensuring that hydrogen evolution reactions (HER) and oxygen evolution reactions (OER) occur separately, thereby preventing the recombination of H₂ and O₂ and guaranteeing the purity of the hydrogen and the safety of the reaction system [15].

 

 

5. Hence, it is recommended to supplement the degradation correlation study of PEM electrolyzers/fuel cells, where the degradation mechanism of the anode Ir catalyst of the PEM electrolyzer (such as IrO₂ dissolution) and the degradation of the cathode Pt of the PEM fuel cell have electrochemical similarities, such as the polarization loss decomposition model in Figure 3 of International Journal of Hydrogen Energy 157 (2025): 150162.

Perfluorinated membrane materials (such as Nafion), noble metal catalysts (Pt and Ir), and precious metal coatings are the largest contributors to the cost of PEM electrolyzer membranes and cells [40]. The cost reduction initiatives focus on decreasing the loadings of noble metals, developing more economical membrane alternatives, and replacing titanium with more cost-effective materials or coatings [41] .Proton exchange membranes (PEM) chemically degrade due to the formation of peroxide at the electrodes, particularly the cathode, and this degradation significantly reduces the efficiency of the cell. Hydrogen peroxide and other reactive oxygen species (ROS) attack and break down the polymer chains within the membrane, causing structural weakening, thinning, and eventual failure, thereby diminishing the membrane's ability to conduct protons and separate gases [42]. "Doping a catalytic layer with materials such as cerium oxide (CeO₂) can enhance the durability of the catalyst and extend the lifespan of the fuel cell by mitigating membrane degradation.[43].

 

 

 

6. Table 1 should be supplemented with a comparison of the quantitative indicators of the three electrolysis technologies: current density (kA/m²), energy consumption (kWh/kg H₂), and platinum group metal usage (g/kW). In particular, the breakthrough of the AEM electrolyzer in precious metal reduction should be emphasized.

 

According to the most recent literature available, the consumption (load) of platinum group metals (PGMs), such as platinum (Pt) and iridium (Ir), in proton exchange membrane (PEM) water electrolysis technology is generally reported as milligrams per square centimeter (mg/cm²) for the electrode area. PEM electrolysis typically uses 0.4 mg/cm² of Pt and 2.5 mg/cm² of IrO₂, which translates to iridium consumption of between 0.67 and 1 g/kW for state-of-the-art stacks [39]. Previous research has indicated that proton exchange membrane electrolysis of water (PEMWE) technology has predicted that the platinum group metal content in the years 2022, 2026 and the final target is 3, 0.5 and 0.125 mg/cm2, along with 0.8, 0.1 and 0.03 g/Kw [40]

 

7. The by-product hydrogen of chlor-alkali production should be analyzed in depth in terms of the mercury pollution risk of the mercury/membrane process and the bottleneck of ion membrane localization. In addition, it is necessary for the author to further supplement the technical economic analysis (TEA) data to compare the membrane/mercury process costs (USD/kg H₂).

According to recent studies, the cost of producing hydrogen using cation exchange membrane technology is around (1.9-2) USD/kgH2, which represents a very competitive economy and environmental benefits compared to mercury cells, which have been gradually replaced due to their toxicity and high operating costs [81],

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

8. hydrogen use coordinated design, and add "hydrogen quality-terminal equipment life coupling mechanism"

 

Hydrogen use

Hydrogen has many versatile uses and is an indispensable component in the decarbonization of a large number of industries. Global hydrogen consumption has grown steadily, from 86 Mt in 2019 to an estimated 100 Mt in 2024[109]. This growth highlights the growing importance of hydrogen in various industrial sectors, such as oil refining, steel production, and the chemical industry, where it is essential for various processes. Table 3 shows the various applications of hydrogen in different sectors.

Category of use	Descripción	R
Energy carrier and storage	Seasonal energy storage to complement intermittent wind and solar power.	[110]
Industrial raw material	Fertilizer production (Haber-Bosch process), refining, and chemical manufacturing.	[111]
Power generation	fuel cells for electricity generation in stationary and portable applications.	[112]
heating medium	Decarbonizing building heating, including residential and commercial heating systems industrial process heating, boiler technologies	[113]
Transport fuel	Cars, buses, trucks, trains, ships, and potentially aircraft powered by hydrogen fuel cells.	[111]
Applications in space	Rocket fuel for propulsion (green hydrogen as a clean combustion propellant)

 

hydrogen purity and cell life

Hydrogen purity requirements vary by application, but common methods like PEM electrolysis and metal membrane purification can achieve high purity levels (99.999% or more), while standard alkaline electrolysis may produce 99.5-99.9% purity requiring further purification for sensitive uses like fuel cells or electronics [45]. Hydrogen purity impacts fuel cell life and, by extension, the overall life cycle cost of hydrogen systems, as lower purity can lead to catalyst degradation, reduced efficiency, and increased replacement frequency [46]. Fuel cells, especially Proton Exchange Membrane Fuel Cells (PEMFCs), require very high purity hydrogen to operate efficiently. Impurities such as moisture, oxygen, nitrogen, carbon monoxide, carbon dioxide, hydrogen sulfide, and ammonia can degrade fuel cell performance [47] .

 

 

Reviewer 2 Report

Comments and Suggestions for Authors

This review covers a significant subject in the development of hydrogen production technologies. The manuscript is written in a consistent way presenting the recent advancements and I believe it would be helpful for scientists in the corresponding fields. The manuscript can be accepted after the following issues are addressed.

Comments:

(1) For hydrogen production technologies, photocatalytic and photoelectrocatalytic systems both represent major approaches to the satisfaction of the demands. Relevant discussions are necessary to enrich the scope of the current review.

(2) In Conclusions section, the authors provided two future directions in the development of hydrogen production technologies, related to the alternatives of feedwater sources and the component optimization of electrolyzers. These demonstrations are made without further elaborations. For catalysts design, yolk-shell nanostructured catalysts, a modified, updated version of core-shell nanostructures, have emerged as a new paradigm for photocatalyst design (DOI:10.1021/acsmaterialslett.4c00790).  The authors may consider provide further insights into these developments to enlighten the readers.

Author Response

Gentlemen

Reviewer

I would like to sincerely thank you for the time and effort you spent reviewing our manuscript. Your valuable comments and constructive suggestions have greatly contributed to improving the quality of our work. We have carefully considered each of your points and have thoroughly addressed them in our response. We appreciate your valuable comments, which helped us to clarify and improve the presentation of our research. Thank you again for your thoughtful and detailed review. We look forward to any further guidance and hope that our revised manuscript will meet your expectations.

 

Dr. Juan Medina Collana

 

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This article systematically reviews the main hydrogen production technologies, including steam methane reforming (SMR) based on fossil fuels, water electrolysis technologies (alkaline electrolysis AWE, proton exchange membrane electrolysis PEMWE, anion exchange membrane electrolysis AEMWE), and by-product recovery of hydrogen in chlor alkali processes. It also explores water purification requirements, hydrogen "color" classification, and their environmental impacts. I recommend to update the paper with minor revision before it can be accepted. The following points are addressed.

• In the introduction section, please clarify the differences between this article and existing literature.
• There are a few grammar and spelling errors (such as "electrolyser" should be "electrolyzer"), it is recommended to conduct detailed language proofreading before the final version.
• The reference format is inconsistent, and some references lack the year and journal name. It is recommended to follow the requirements of the journal "Sustainability" for standardization.

Author Response

Gentlemen

Reviewer

I would like to sincerely thank you for the time and effort you spent reviewing our manuscript. Your valuable comments and constructive suggestions have greatly contributed to improving the quality of our work. We have carefully considered each of your points and have thoroughly addressed them in our response. We appreciate your valuable comments, which helped us to clarify and improve the presentation of our research. Thank you again for your thoughtful and detailed review. We look forward to any further guidance and hope that our revised manuscript will meet your expectations.

Dr. Juan Medina Collana

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

Thank you for the opportunity to review this manuscript titled “Analysis of the Main Hydrogen Production Technologies.” The topic is highly relevant for the sustainable energy transition. The manuscript offers a broad overview of hydrogen production technologies, including fossil-based and renewable pathways, with useful process diagrams and comparative tables. To help strengthen the paper further, I offer the following questions and suggestions:

1. Could you please clarify more explicitly in the introduction what specific new contribution or perspective this review adds compared to existing reviews? For example, do you aim to identify research gaps, highlight recent advances, or evaluate costs in detail?
2. The section on water electrolysis is well developed, but the coverage of steam methane reforming (SMR) is relatively brief. Would you consider expanding on SMR with carbon capture (blue hydrogen), current capture rates, or storage challenges?
3. How do the different technologies compare in technology readiness level (TRL)?
4. What are their comparative cost projections and uncertainties?
5. What are the environmental trade-offs, such as water use in electrolysis versus fossil reforming with CCS?
6. How might carbon pricing or renewable energy costs affect competitiveness?
7. Table 1 uses terms such as “Nafion” and “Zirfon” without explanation. Could you add short clarifications or footnotes for readers less familiar with these materials?
8. Would you consider simplifying or consolidating the detailed chemical reaction sections to improve flow for a broad sustainability audience?
9. What research priorities do you see as most urgent?
10. What policy measures might help accelerate green hydrogen production?
11. Have you checked unit consistency throughout (e.g., kWh/kg vs kWh/Nm³ in tables)?
12. Are all figures and tables fully captioned so they can stand alone?
13. Have you standardized the formatting of references?

 

Author Response

Gentlemen

Reviewer

I would like to sincerely thank you for the time and effort you spent reviewing our manuscript. Your valuable comments and constructive suggestions have greatly contributed to improving the quality of our work. We have carefully considered each of your points and have thoroughly addressed them in our response. We appreciate your valuable comments, which helped us to clarify and improve the presentation of our research. Thank you again for your thoughtful and detailed review. We look forward to any further guidance and hope that our revised manuscript will meet your expectations.

 

Gentlemen

Reviewer

I would like to sincerely thank you for the time and effort you spent reviewing our manuscript. Your valuable comments and constructive suggestions have greatly contributed to improving the quality of our work. We have carefully considered each of your points and have thoroughly addressed them in our response. We appreciate your valuable comments, which helped us to clarify and improve the presentation of our research. Thank you again for your thoughtful and detailed review. We look forward to any further guidance and hope that our revised manuscript will meet your expectations.

 

Dr. Juan Medina Collana

 

 

Author Response File: Author Response.pdf

Reviewer 5 Report

Comments and Suggestions for Authors

This article discusses ways to produce hydrogen. The authors consider both the large-scale production of gray hydrogen by steam reforming of natural gas and the production of hydrogen by electrolysis of water. In this review, the authors conduct a comparative analysis of these methods for producing hydrogen. This study is relevant because the use of hydrogen as an energy resource will really reduce carbon oxides emissions into the atmosphere and improve the environment.

Unfortunately, in my opinion, this article has low scientific value. There is not enough scientific novelty in it. I have a number of comments:

1. Indeed, hydrogen is widely used: as a fuel, as a raw material for the industrial production of large-tonnage petrochemical products such as ammonia, methanol, dimethyl ether, etc. In this case, hydrogen is considered as an energy resource that can be transported or obtained directly at the place of its use. There are also various methods for producing hydrogen – large-scale, such as steam conversion and autothermal reforming of natural gas, as well as low-tonnage, such as electrolysis. There are industrially implemented methods and there are those that are under development. Therefore, when conducting a comparative analysis of methods for producing hydrogen, it is necessary to indicate the boundaries within which this comparison is made: the use of hydrogen, production volumes, cost of hydrogen, its purity, scope of application, environmental friendliness, remoteness of the place of its consumption from the place of its production, etc.

In this article, the authors do not specify the comparison criteria by which these methods of hydrogen production were selected.

- For example, if it is environmentally friendly, then it makes no sense to compare steam reforming of methane with electrolysis, since obtaining hydrogen from carbon-containing raw materials will naturally be worse than obtaining hydrogen from water. Moreover, first of all, not because a synthesis gas containing COx in addition to hydrogen is obtained, but because, in order to convert the 1st volume of natural gas, it is necessary to additionally burn about 0.7-0.8 volumes of natural gas to generate the necessary heat. This leads to huge emissions of carbon oxides into the atmosphere.

- If hydrogen is considered as a raw material for producing, for example, methanol, then when using natural gas as a raw material, carbon oxides are obtained, which, on the contrary, are needed for the synthesis of the methanol molecule. When using electrolysis, only hydrogen is obtained and carbon oxides must be taken from somewhere outside, which greatly complicates the method of obtaining methanol.

- If hydrogen is considered as an environmentally friendly fuel for energy production, then it is necessary to conduct a comparative analysis of only ecological methods of its production, for example, electrolysis. And then the criterion of comparison will be its cost, the possibility of storage and transportation to the place of its consumption.

and the like.

In my opinion, the authors need to specify more competitively the criteria by which the selection of methods for producing hydrogen was carried out.

2. Also, in my opinion, the presented analysis of methods for producing green hydrogen is very superficial. I did not find any new information for myself in the presented study. A superficial description of electrolytic methods for producing hydrogen from water is presented without a detailed assessment. There is no economic comparative assessment of the application of the considered methods (capital and/or operating costs), nor an assessment of the possibility of scaling, etc.

In my opinion, the authors should, first of all, choose the field of application and the type of hydrogen that they will consider – blue, green, gray, raw materials for the production of petrochemical products, fuel, production volume, etc. Choose methods for producing hydrogen. Then it is necessary to determine the comparison parameters – the cost of hydrogen, the complexity of production, whether additional raw materials are needed, energy costs, the possibility of scaling, etc., and after that, conduct a detailed, in-depth analysis of the selected methods for producing hydrogen.

Author Response

I would like to sincerely thank you for the time and effort you dedicated to reviewing our manuscript. Your valuable comments and constructive suggestions have greatly contributed to improving the quality of our work. We have carefully considered each of your points and have comprehensively addressed them in our response. We appreciate your valuable comments, which helped us clarify and improve the presentation of our research. Thank you again for your thoughtful and detailed review. We look forward to any further guidance and hope that our revised manuscript meets your expectations.

Author Response File: Author Response.pdf

Round 2

Reviewer 4 Report

Comments and Suggestions for Authors

N/A

Reviewer 5 Report

Comments and Suggestions for Authors

The explanations of the authors of the article completely satisfied me. In my opinion, this article can be published in the "Sustainability" journal. Thanks to the authors for the work done.