The Effect of Tourmaline on SCR Denitrification Activity of MnO_x/TiO₂ at Low Temperature

Round 1

Reviewer 1 Report

I think that the topic is important and interesting, however I miss some important information and experiments that needs to be added/improved before publication, described below.

1. Line 81-82 states that the impact from 10% doping is tremendous, which I think is not describing the influence. There is a significant improvement with 10% doping, but not tremendous.
2. Line 88, the authors state that 10% doping is the optimum, and that is true among the 0, 5, 10, 20 % doping that is tested in experiments. However, It would not be surprising if for instance 12 or 15% (or 8) would be even better. I would like to see a doping in the interval between 10 and 15.
3. In the analysis of surface acid sites (line 180-204), only 0 and 10% doping is included. Even though 10% was the optimum (according to the authors), analysing only this doping amount will not give a full view of how the acid sites will vary with doping. I would very much like to see ammonium-TPDs also for the other doping amounts, in order to be able to draw sound conclusions.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Review of paper “Study the low-temperature SCR property of MnOx/TiO2 doped with tourmaline through density functional theory (DFT)” prepared by Yizhe Helian, Suping Cui and Xiaoyu Ma.

The manuscript catalysts-908957 reports method of modification of SCR catalyst by addition of boron silicate mineral (tourmaline), and the experimental results of NOx conversion and DFT calculation. The paper reviewed contains interesting results. However, some aspects should be discussed in more detail. In my opinion this article is worth to be published in Catalysts after minor revision. I have some suggestions/questions which authors may consider prior to publication of this work:

1. There are no analysis of the application or potential application of the proposed systems in the real systems. This aspect should be discussed in the context of the characteristics of the materials obtained.
   1. The authors could at least estimate the difference in the cost of obtaining such catalysts. Would the economic aspect be beneficial in taking into account the efficiency improvements in the conversion process?
   2. According to the information presented in the paper, natural black tourmaline from Chifeng area, Inner Mongolia, China was used for research. It is obvious that the authors use national sources. Nevertheless, due to the fact that this mineral has different forms and compositions, do the authors consider that similar results would be obtained for the other minerals in this group of compounds? Which characteristics of the material contribute to such conversion results? Can the presented in the paper be applied to other mineral from tourmalines? Is it possible to expect a simple transfer of results or would it require further research without a guarantee of success? Can the results be scaled up?
2. The authors should indicate the measurement error for all experimental studies. Such an approach would make the results reliable, especially since in many cases discrepancies between the results (fluctuations) are observed. For example, the results presented in Figure 1 do not show unequivocally trends in NOx conversion depending on the addition of the mineral, at 125oC the values are similar for all analysed compositions except for 10% tourmaline addition and at 150oC except for the pure catalyst.
3. Since the conversion results depend on time, as shown in Figure 2, the measurement time of the results shown in Figure 1 should be added to the description.
4. The quality of XRD diagrams (Figure 3 and 4) should be improved. In its current form, it is difficult to see the relevant peaks.
5. The subject of the work should be changed. Neither in the abstract nor in the conclusions the authors mention anything about DFT, which confirms that the authors focused on obtaining and evaluating the properties of catalysts and the calculations were only a marginal part of the analysis.
6. There are several editorial errors, such as “1” in the title, bold letters in keywords, two brackets for references in the text, lack of reference in page 8, line 220, different font size (line 82, 206-220), [J] in references, lack of full bibliography ([1], [10], [14], [15], [18], [19], [21]).

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

I think that the manuscript is now ok for publication.