Investigation of Phosphorus Loaded V2O5/ZrO2 Catalysts for the Oxidative Dehydrogenation of Propane (ODH)
, Hanane Mahir 2, Adnane El Hamidi 2, Mohamed Kacimi 2 and Leonarda Francesca Liotta 3,*
Round 1
Reviewer 1 Report
Since there is a lot of data in the article, the results are poorly perceived. Perhaps the authors should change the order of presentation of the results. First, in the article, it is necessary to present the results of a study of the acid-base and redox properties of the V2O5/ZrO2 systems, then - of acid-basic and redox properties of phosphorus-modified V2O5/ZrO2, after that – the properties of the catalysts in the oxidative dehydrogenation of propane. After that, it is possible to give a study of the physicochemical properties of the samples and, on the basis of this, explain the results.
As before, there are many typos and inaccuracies in the article: ERP – in the annotation and introduction, ESR – in the Results and Discussion; Figure 5, but Fig. 7; UV-Vis-Dir (line 176), but UV-Vis-Dir (capture of the Fig. 5). There are no subscripts in the capture of Table 1. In Introduction (lines 74- 75) was written «the acid-base properties and redox catalysts». Maybe authors mean «the acid-base and redox properties of the catalysts»?
I meant that in the text it is worthwhile to give a scheme for the reactions of butanol transformation on active centers of different nature, indicating the presence or absence of oxygen in each of the reactions. This would make the understanding of the text more visual and easier.
Author Response
We would like to thank the reviewer for comments and suggestions. Our responses are reported in the attached file.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments are attached.
Comments for author File: Comments.pdf
Author Response
We would like to thank the reviewer for comments and suggestions.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments to the authors
The present manuscript reports interesting results concerning the preparation of phosphorus loaded V2O5/ZrO2 catalysts for the oxidative dehydrogenation of propane. Currently, production of olefins from other organic compounds is the hot area of research due to their huge demands from various industries. The present work affords a promising strategy for the designing effective catalyst for the oxidative dehydrogenation of propane to olefins. I suggest minor revision for quality enhancement, which are given bellow.
11. The manuscript contains grammatical and typographical mistakes which should be carefully read and remove and the language need improvement.
22. The sentence in the first paragraph “On the other hand, the huge demand for olefins as a feedstock for various industries” is senseless. Correct it. Also check line 77-78.
33. Discuss some catalytic applications of ZrO2 and V2O5 nanoparticles in the introduction of the manuscript.
44. Put table 1 after the figure 3 as it is discussed after the discussion of figure 3.
55. Line 161, Correct ZrO2 as ZrO2.
66. Mention some uses of the targeted product propene in the introduction.
77. The authors should properly correlate the XRD and FTIR data with the results presented in the manuscript.
88. Line 212, correct the sentence as “and EDX analysis for the elemental mapping distribution.”
99. Provide the EDX spectra figure and put the table 2 inside the EDX figure.
110. Authors are suggested to perform TEM analysis to deeply investigate the interaction of catalysts components.
111. How these organic compounds are stable at high reaction temperature.
112. The authors are suggested to check the sustainability of the catalysts.
113. The materials section in the experimental section is missing. Insert this section and provides all chemicals and their specifications.
114. Cite the following articles to improve the scientific quality of the paper. Explain the affecting parameters with the help from these reviews and cite in the manuscript “ Journal of Environmental Health Science and Engineering (2020) 18:1473–1489; Applied Water Science (2018) 8:60 https://doi.org/10.1007/s13201-018-0709-7”.
Author Response
We would like to thank the reviewer for comments and suggestions. Our responses are reported in the attached file.
Author Response File: Author Response.pdf
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
1. The illustration about Figure 1 must be corrected becuase the decribed data are opposite to that in the figure.
2. In Line 111-112, the author claimed that "remaining at a conversion of about 4%". How can such a low conversion get high yields to butene and butanone?
3. TOF value is often calculated based on the conversion of reactant. While in Figure 2, 9, 15 and 16, the TOF were calculated based on the products. Please supplement the calculation method in the experimental section.
4. The English language and style should be re-checked, such as superscript, subscript, and punctuation.
Reviewer 2 Report
The article is devoted to the study of the V2O5/ZrO2 samples modified by phosphate adding as catalysts for the oxidative dehydrogenation (ODH) of propane. There are lot of experimental data in the article. However, the article cannot be published in the submitted version. It needs serious reworking. The article is overloaded with data. It should be divided into two separate parts.
The main comments are shown below.
1. It is necessary to give schemes of the studied reactions in the text of the article, as well as indicate on them the conditions under which certain products are obtained.
2. The data presented in Fig. 1 do not agree with the description in the text. According to Fig. 1, the yield of butenes increases with increasing content of V2O5, reaches a maximum value and then remains unchanged. The text indicates that such a dependence is characteristic of the formation of methyl ethyl ketone.
3. Expression «increase of catalyst » is incorrect (line 118). Probably, it would be more correct to state that TOF increased with increase of the V2O5 content.
4. There is no conclusion about the choice of a system with a content of vanadium 3.6 before part 2.2.
5. Texture data is not analyzed in any way in the text of the article.
6. It is necessary to designate the bands at 894 sm-1 in Fig. 4.
7. There is no explanation for the absence of the band in Fig. 5 at P/V=1. Are obtained data reproducible?
8. It is necessary to introduce a common terminology at lines 184-197 (ESR or EPR).
9. On the basis of the presented SEM micrographs, it is impossible to draw a correct conclusion about the effect of the amount of phosphorus on the particle size. It is necessary to bring micrographs at higher and lower magnifications (for example, into Supplementary part).
10. There is a repetition of the previously given information in lines 215 - 218.
11. For ease of perception, the color of the curves in Figures 8 and 9 corresponding to the same products should match.
12. line 241: the text does not indicate that the data given refer to TOFene.
13. Fig. 10 and 11 are incorrect. It is better not to connect the points with lines. For example, on the curve at 450 C, a maximum is distinguished at a V2O5 content of 6wt%. However, there are no experimental data for this point.
14. It remains unclear why the authors previously estimated the acid-base properties of the sample without adding phosphorus, if later the properties of all samples were studied in the reaction of oxidative dehydrogenation of propane. The data on the evaluation of the acid-base properties of samples using the butanol dehydrogenation reaction should be better singled out in a separate article.
15. The article is very sloppy. In the text of the article, subscripts are not always highlighted (line 149), dots appear in the middle of a sentence (line 114), there is slang (line 141 «without fogetting»).
Reviewer 3 Report
This manuscript deals on the investigation of phosphorus loaded V2O5/ZrO2 catalysts for the dehydrogenation of 2- butanol and for the oxidative dehydrogenation of propane.
The manuscript contains some valuable information of interest for the wide scientific community interested in this kind of compounds, but the manuscript would need extensive corrections before it could be considered for publication.
- The title of the article is not correct as the main catalytic reaction studied by the authors is the 2-butanol dehydrogenation
- Page 3 - confuse phrase …in N2 and 2-butanol mixture, the supports V2O5/ZrO2 and modified catalysts show formation of 5% and 2.5% of methyl ethyl ketone (MEK) and butenes produced via dehydrogenation and dehydration respectively.
- It is a complete confusion in description of Figure 1. When is discussed about the butenes production the authors are referring to the butanone curve of the graph, and vice versa.
- Page 4-5: How could be explain the increase of surface area when P/V=0.5?
- Incorrect phrase: lines 205-206: “This could be due to the vanadate and phosphate supported phases are amorphous.”
- My recommendation is to move chapter 2.1. Butanol dehydrogenation over V2O5/ZrO2 to 2.3. Catalytic activity.
- For Fig. 2, fig. 8, 9 and 16, the meaning of labels (TOF ene, TOF one) should be explain in the text and caption of the figures.
- Which are the other reaction products for both catalytic reactions 2-butanol dehydrogenation and oxidative dehydrogenation of propane, respectively? My recommendation is to calculate carbon balance and should show the yield of the by-products.
- Did the authors find coke deposition on spent catalysts, especially for 2-butanol dehydrogenation?
In summary, I will recommend this paper for publication only after corrections.
