Aerosol-Assisted Synthesis of Sn–Si Composite Oxide Microspheres with the Hollow Mesoporous Structure for Baeyer–Villiger Oxidation

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Report on the manuscript catalysts-2676819 entitled “Aerosol-assisted synthesis of Sn-Si composite oxide hollow mesoporous microspheres and its catalytic performance in Baeyer-Villiger oxidation”. The submitted manuscript should be revised. This work represented the incorporating tetravalent Sn species into the silica framework such as zeolite or oxide possess Lewis acidic property and an aerosol-assisted method was used to prepare Sn-Si composite oxide microspheres using CTAB as template. The method is based on the formation of aerosol from a solution of Sn, Si precursors and template (CTAB). The introduced material exhibited acceptable catalytic performances in the Baeyer-Villiger oxidation of 2-adamantanone by using H2O2. In short, the following points should be addressed:

1.   The language of the manuscript should be revised.

2.   CTAB template should be in the “Keywords” of the manuscript.

3.   A new paragraph in the introduction should be inserted about the reported nanoparticles using CTAB and the advantages of using this method.

4.   In XRD analysis, what is the JCPDS of the XRD data and how the authors carried out the low angle XRD?

5.   In line 99, “indicating the absence of a regular mesoporous structure”, what is the proof of this such as references indicated the same conclusion.

6.   What about Baeyer-Villiger oxidation of bulk 2-adaman-tanone with H2O2 without catalyst?, it should be clear that it could be carried out after long time, or no oxidation could be seen?

7.   Reuse runs are few, could the authors increase it to check the availability of reusing the introduced catalyst.

8.   Could the authors add schematic mechanism of the Baeyer-Villiger oxidation to easily understand the role of the utilized catalyst?

9.   The self-citation of the first author could be decreased.

 The first author has 6 self citation which should be decreased to two or 3 at most as the following:   1. "Our group developed an aerosol-assisted hydrothermal method to synthesize zeolites [22-25]", only one reference is enough. 2. "The Sn-Si composite oxide produced by aerosol process was act as the precursor for the further crystallization of Sn-Beta zeolite [25-28]", only one reference is enough.

2. "The Sn-Si-30-0 exhibits a regular solid spherical morphology with a particle size of approximately 2 µm as shown in Figure 2(a), which is similar to our previous report [25, 27]" no need to compare morphology and if they compared, just one reference is enough. Comments on the Quality of English Language

It should be revised.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Concerning the scientific worth of the manuscript, there are some points, which I would like to raise in order to improve the quality of manuscript in order to make it acceptable for Catalysts.

 These should all be taken in account in order to deliver a more solid manuscript.

1)      In our opinion, in the abstract it is necessary to provide more specific data on the obtained Sn-Si composite oxides hollow mesoporous microspheres and their catalytic properties.

2)      The aerosol spray method should be described in more detail, indicating the physical parameters of the process.

3)      What determines the choice of long-chain CTABr as template? Does the template structure affect the morphology of the samples?

4)      The authors explain the catalytic efficiency of the samples by their morphology and textural characteristics, which are influenced by the amount of used CTABr. What can one say about the Lewis acidity of these samples?

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This manuscript deals with the Aerosol-assisted preparation of Sn-Si composite oxide hollow mesoporous microspheres and its catalytic performance in Baeyer-Villiger oxidation.

            The manuscript contains very valuable information of interest for the wide scientific community interested in this kind of compounds. In my opinion the manuscript could be considered for publication in present form with only some small observations

1.      Page 3: Which is the meaning of FWHM?

2.      Page 4: In Figure 3 the values of Y axe are missing

3.      In my opinion, the conclusions are too few compared to the amount of data in the manuscript

In summary, I will recommend this paper for publication after corrections.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Accepted

Author Response

Thank you very much for the efforts on reviewing our manuscript.

Reviewer 2 Report

Comments and Suggestions for Authors

 Authors corrected text and give answers to all comments  

Author Response

Thank you very much for the efforts on reviewing our manuscript.