Applicability of Nickel-Based Catalytic Systems for Hydrodehalogenation of Recalcitrant Halogenated Aromatic Compounds

Round 1

Reviewer 1 Report

The review entitled "Applicability of nickel-based catalytic systems for hydrodehalogenation of recalcitrant halogenated aromatic compounds" by Tomáš Weidlich is well written and well organized. This work contains the most important information about nickel-based catalytic systems in hydrodehalogenation.  The work is based on a large number of references, which is a significant advantage of the review.  Schemes and drawings are made very carefully. But I noticed a few things that should be improved:

In the abstract and the introduction it should be written what years this work covers.  

It would be advisable to add information on the possible multiplicity of the use of given catalytic systems, their TON and TOF numbers. 

In conclusion part, a paragraph should be added with information as to what and further research should be undertaken in the future on nickel-based catalytic systems 

Information on the yield of the presented reactions should be added to the schemes.

Author Response

Dear reviewer, thank you very much for your fruitful comments. I tried to improve my review using your guidance.

The review entitled "Applicability of nickel-based catalytic systems for hydrodehalogenation of recalcitrant halogenated aromatic compounds" by Tomáš Weidlich is well written and well organized. This work contains the most important information about nickel-based catalytic systems in hydrodehalogenation.  The work is based on a large number of references, which is a significant advantage of the review.  Schemes and drawings are made very carefully. But I noticed a few things that should be improved:

In the abstract and the introduction it should be written what years this work covers.  

In fact, the literature retrieval was made using Web of Science (WOS) source without time limitations using key words „hydrodehalogenation“ or „hydrodechlorination“ AND „Ni“ AND „chlorobenzene“ (or „aromatic“, etc.). The cited references was obtained eighter directly from WOS or as citation of references found herein articles found using WOS. Actually, this review contains references since 1990 (among the few exceptions).

It would be advisable to add information on the possible multiplicity of the use of given catalytic systems, their TON and TOF numbers.

I hope that I added the required data according to the available published information sources, as you can see.

In conclusion part, a paragraph should be added with information as to what and further research should be undertaken in the future on nickel-based catalytic systems.

The required paragraph is added.

Information on the yield of the presented reactions should be added to the schemes.

I added the required data in text of manuscript and/or in schemes. In many cases, I used mainly conversion which is, as I hope, the most important information for readers focused on effectivity of hydrodehalogenation reactions based on Ni catalysis.

Author Response File: Author Response.pdf

Reviewer 2 Report

Reviewer’s Comments:

A manuscript entitled:

“Applicability of nickel-based catalytic systems for hydro-dehalogenation of recalcitrant halogenated aromatic compounds” presented by:

[Tomáš Weidlich]

was submitted to Catalysts (an MDPI Journal) for review on 5^th November 2021.

A: General Comments

1. Type of article: Review

The content presented befits the selected type of journal.

2. Manuscript Title:

The title is appropriate for the review article.

3. Abstract:

The abstract aptly summarizes some recent developments on the use of nickel as a non-precious metal catalyst in environmental applications.

4. Introduction:

• The background in the literature overview motivates well for why nickel should be applied in hydro-dehalogenation (HDH) of halogenated aromatic compounds (Ar-Xs), particularly when compared to the use of PGMs.
• After the introduction (presented as ‘Heading 1’), the manuscripts lacks other ‘Headings’ at Level 1 and ‘sub-headings’ at Level 2 or 3.

5. The Body:

This review highlights the successes and difficulties various researchers have encountered in trying to make aromatic halides less toxic and more biodegradable in the environment. The work is impressive, and the content, which discusses hydrogenolysis carried out in both gas phase and liquid phase is relevant to this periodical as it resonates well with the readers’ interests.

The major criticism is in the presentation of the content. The author should try and minimize the use of long complex sentences that carry multiple ideas: breaking up each idea into one sentence. Sometimes, we have one sentence paragraphs, whose ideas can be merged into appropriate paragraphs of at least 4 – 5 sentences (minimum).

• Examples of long sentences that can be broken down:

Lines 81 – 84;

Lines 104 – 108;

Lines 181 – 186;

Lines 308 – 311;

Lines 376 – 378;

Lines 389 – 392;

Lines 402 – 406;

Lines 473 – 489;

Lines 513 – 517;

Lines 554 – 557;

Lines 608 – 613.

• Examples of one sentence paragraph that can be merged with other texts:

Lines 49 – 57;

Lines 65 – 66;

Lines 229 – 230;

Lines 283 – 284;

Lines 399 – 401;

Lines 435 – 438;

Lines 488 – 489;

6. Conclusion: This work displays a notable understanding of the role of Ni catalyst in the hydro-dehalogenation of aromatic halides. The manuscript certainly characterizes a significant effort that should be recognized by publishing the article, but with major improvements to the aesthetics, flow of ideas and general presentation of the manuscript. The draft contains some very long complex sentences that can be condensed to keep the ideas separate and more concise. For example, many long sentences can be broken into several short statements, with each sentence dealing with only one aspect or idea at a time. Therefore, the manuscript should be accepted for publication with major corrections.

B: Minor Issues (Aesthetics)

7. Line 75: Correct the subscripts in “Ni/Al2O3”.
8. Line 86: What is HDC? Is it hydro-dechlorination? It may not be obvious to all readers unless it is clearly defined somewhere in the text as early as this, and not later.
9. Line 90: This sentence “Ni on γ-alumina has a lower activity than on the active carbon supported Ni” might sound better like this: “Ni on γ-alumina has a lower activity than when supported on active carbon.”
10. Line 162: What is the meaning of the 2 arrows in the second half of the equation?
11. Line 220: Is this subtitle intended to mean “Hydrogen Transfer in Ni-catalyzed hydro-dehalogenation reactions”?
12. Line 258: What is C_ary-Cl bond?
13. Line 286: Did you want to say: “This drawback is potentially removed by the method described by Lipshutz et al., ?
14. Line 383: Insert space between H₂ and the reference in: “gaseous H₂[80]”.
15. Line 402: Revise the phrase “Especially commercially simply available”
16. Line 427: Did you want to say: “into ‘a’ mixture ‘OF’ nonhalogenated phenols”? Please consider revising the sentence.
17. Line 461: Did you want to say: “is accompanied by”?
18. Lines 488 – 489: Did you want to say: “successfully tested ‘INCLUDING THE’ treatment of contaminated water streams ‘ON A’ pilot plant scale”?
19. Lines 496 – 497: Did you want to say: “…the ‘kinetics’ of HDH ‘in’ Ar-Xs is extremely slow even ‘when’ using nanoparticles.”?
20. Line 670: Correct the subscripts in “Ni/NiAl2O4” of Reference 15 and all the other citations in the manuscript such as Line 699 (Ni/SiO2), Line 715 (H2), and Line 760 (NaBH4), among others.

 

Comments for author File: Comments.pdf

Author Response

Dear reviewer, thank you very much for your fruitful comments. I tried to improve my review using your guidance.

Thank you very much for your improvements of my English writing. Unfortunately, I am not the native English speaker. The below mentioned misunderstandings remained in my text even after proofreading by native English speaker.

Reviewer’s Comments:

A manuscript entitled:

“Applicability of nickel-based catalytic systems for hydro-dehalogenation of recalcitrant halogenated aromatic compounds” presented by:

[Tomáš Weidlich]

was submitted to Catalysts (an MDPI Journal) for review on 5^th November 2021.

A: General Comments

1. Type of article: Review

The content presented befits the selected type of journal.

1. Manuscript Title:

The title is appropriate for the review article.

1. Abstract:

The abstract aptly summarizes some recent developments on the use of nickel as a non-precious metal catalyst in environmental applications.

1. Introduction:

• The background in the literature overview motivates well for why nickel should be applied in hydro-dehalogenation (HDH) of halogenated aromatic compounds (Ar-Xs), particularly when compared to the use of PGMs.
• After the introduction (presented as ‘Heading 1’), the manuscripts lacks other ‘Headings’ at Level 1 and ‘sub-headings’ at Level 2 or 3.

I added the required headings, as you can see.

 

 

1. The Body:

This review highlights the successes and difficulties various researchers have encountered in trying to make aromatic halides less toxic and more biodegradable in the environment. The work is impressive, and the content, which discusses hydrogenolysis carried out in both gas phase and liquid phase is relevant to this periodical as it resonates well with the readers’ interests.

The major criticism is in the presentation of the content. The author should try and minimize the use of long complex sentences that carry multiple ideas: breaking up each idea into one sentence. Sometimes, we have one sentence paragraphs, whose ideas can be merged into appropriate paragraphs of at least 4 – 5 sentences (minimum).

I tried to improve the manuscript according to your above-mentioned comments.

• Examples of long sentences that can be broken down:

Lines 81 – 84;

Lines 104 – 108;

Lines 181 – 186;

Lines 308 – 311;

Lines 376 – 378;

Lines 389 – 392;

Lines 402 – 406;

Lines 473 – 489;

Lines 513 – 517;

Lines 554 – 557;

Lines 608 – 613.

I tried to improve the manuscript according to your above-mentioned comments.

 

• Examples of one sentence paragraph that can be merged with other texts:

Lines 49 – 57;

Lines 65 – 66;

Lines 229 – 230;

Lines 283 – 284;

Lines 399 – 401;

Lines 435 – 438;

Lines 488 – 489;

I hope that I understood well these your comments and improved the manuscript correctly.

1. Conclusion: This work displays a notable understanding of the role of Ni catalyst in the hydro-dehalogenation of aromatic halides. The manuscript certainly characterizes a significant effort that should be recognized by publishing the article, but with major improvements to the aesthetics, flow of ideas and general presentation of the manuscript. The draft contains some very long complex sentences that can be condensed to keep the ideas separate and more concise. For example, many long sentences can be broken into several short statements, with each sentence dealing with only one aspect or idea at a time. Therefore, the manuscript should be accepted for publication with major corrections.

I hope that I improved the manuscript correctly according to your comments.

B: Minor Issues (Aesthetics)

1. Line 75: Correct the subscripts in “Ni/Al2O3”.
2. Line 86: What is HDC? Is it hydro-dechlorination? It may not be obvious to all readers unless it is clearly defined somewhere in the text as early as this, and not later.
3. Line 90: This sentence “Ni on γ-alumina has a lower activity than on the active carbon supported Ni” might sound better like this: “Ni on γ-alumina has a lower activity than when supported on active carbon.”
4. Line 162: What is the meaning of the 2 arrows in the second half of the equation? Sorry for this misunderstanding, it is used sometimes in organic chemistry for illustrating several repeated (principally the same) reactions.
5. Line 220: Is this subtitle intended to mean “Hydrogen Transfer in Ni-catalyzed hydro-dehalogenation reactions”?
6. Line 258: What is C_ary-Cl bond? Sorry for this misunderstanding, it is used in organic chemistry area for specifying corresponding C_sp2-halogen bond
7. Line 286: Did you want to say: “This drawback is potentially removed by the method described by Lipshutz et al., ?
8. Line 383: Insert space between H₂ and the reference in: “gaseous H₂[80]”.
9. Line 402: Revise the phrase “Especially commercially simply available”
10. Line 427: Did you want to say: “into ‘a’ mixture ‘OF’ nonhalogenated phenols”? Please consider revising the sentence.
11. Line 461: Did you want to say: “is accompanied by”?
12. Lines 488 – 489: Did you want to say: “successfully tested ‘INCLUDING THE’ treatment of contaminated water streams ‘ON A’ pilot plant scale”?
13. Lines 496 – 497: Did you want to say: “…the ‘kinetics’ of HDH ‘in’ Ar-Xs is extremely slow even ‘when’ using nanoparticles.”?
14. Line 670: Correct the subscripts in “Ni/NiAl2O4” of Reference 15 and all the other citations in the manuscript such as Line 699 (Ni/SiO2), Line 715 (H2), and Line 760 (NaBH4), among others.

 

I hope that I improved the manuscript correctly according to your above-mentioned comments.

Author Response File: Author Response.pdf

Reviewer 3 Report

The paper is a review of using nickel catalysts for hydrodehalogenation.  The paper covers nickel on alumina or silica as well as Raney nickel using gasous hydrogen.  It also includes information on hydrogen transfer using non-molecular hydrogen.  Finally, the paper discusses the recycle of nickel catalysts.

 

The paper discusses nickel versus platinum group metals.  Is there literature around other non-PGM metals?  The paper also lacks a discussion of how much better or worse nickel is than PGMs or non-PGMs.

Author Response

Dear reviewer, thank you very much for your fruitful comments. I tried to improve my review using your guidance.

 

The paper is a review of using nickel catalysts for hydrodehalogenation.  The paper covers nickel on alumina or silica as well as Raney nickel using gasous hydrogen.  It also includes information on hydrogen transfer using non-molecular hydrogen.  Finally, the paper discusses the recycle of nickel catalysts.

The paper discusses nickel versus platinum group metals. Is there literature around other non-PGM metals? 

Yes, it is (W, Mo, Co, Fe). However, the proposed manuscript is focused on application of Ni for hydrodechlorination of halogenated aromatic compounds and I hope that it will be the part of Special Issue "Recent Advances in Nickel-Based Catalysts". I added references containing information for comparison of Ni-based catalysts with other non-PGM metals based, for example reference No. 13.

The paper also lacks a discussion of how much better or worse nickel is than PGMs or non-PGMs.

I added the required information in the text of my manuscript and expanded the Reference chapter with appropriate articles.

Author Response File: Author Response.pdf