Comparative Study of α- and β-MnO2 on Methyl Mercaptan Decomposition: The Role of Oxygen Vacancies
Round 1
Reviewer 1 Report
The work from Hong Su et al describes the synthesis and catalytic activity of MnO2 nanorods with different crystalline structure, alpha and beta phases. The authors observed a higher activity for the alpha phase and related it to the higher oxygen vacancy concentration. The authors prove the presence of these defects with different techniques, in particular I believe and suggest them to revise this part. They show frequency filtered maps obtained from HRTEM images indicating the presence of these defects, I believe the images they show are not sufficient to prove the presence of the defects therefore they should improve the corresponding section.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
It is an interesting paper on the synthesis of α-MnO2 and β-MnO2 examined in the decomposition of methyl mercaptan. The catalysts were fully characterized by nitrogen adsorption/desorption, XRD, XPS, HRTEM, SEM, H2-TPR, O2-TPD and Raman spectroscopy. It is a meaningful work. Nevertheless, I suggest making some minor corrections before its publication in Nanomaterials:
1. What amount of water was used for the washing of catalysts after centrifugation? Please add this detail in Materials and Methods Section.
2. The lines 167, 171: styrene should be replaced by methyl mercaptan.
3. The line 185: The XRD peaks assigned to β-MnO2 are wrong (they belong to α-MnO2 structure). Please add the correct ones.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
I thank the authors for describing better the oxygen defects evaluation.
