A DFT Study on Single Brønsted Acid Sites in Zeolite Beta and Their Interaction with Probe Molecules
Round 1
Reviewer 1 Report
The Authors focus on the Single Bronsted Acid Sites in Zeolite Beta using computations with PBE functional including DFT-D3 correction and TZV2P as well as TZVP basis sets. There are two problems about the manuscript.
1. there are too many references about the background. The authors should add more references related to density functional theory (DFT) calculations.
2.The whole manuscript discussed the Bronsted acid sites and their interaction with the probe molecules. It is better to add some other representational measurements to support your conclusion
Author Response
The reviewer wrote:
The Authors focus on the Single Bronsted Acid Sites in Zeolite Beta using computations with PBE functional including DFT-D3 correction and TZV2P as well as TZVP basis sets. There are two problems about the manuscript.
- there are too many references about the background. The authors should add more references related to density functional theory (DFT) calculations.
Reply
We thank the reviewer for the comments. References related to DFT have been added to the manuscript. Reference to CP2K program, GPW approach, DFT and PBE methods have been added.
The reviewer wrote:
2.The whole manuscript discussed the Bronsted acid sites and their interaction with the probe molecules. It is better to add some other representational measurements to support your conclusion
Reply:
In this manuscript, we investigated acidity and adsorption of test molecules over zeolite beta model. It is concluded that adsorption energy of a series of test molecules does not correlate with the acid strength of the acid sites. We limit the research to zeolite beta and test molecules acetonitrile, dimethyl sulfide, dimethyl sulfoxide, isothiazole, pyridine, tetrahydrofuran and ammonia.
Reviewer 2 Report
The manuscript studied the single Brønsted acid sites in zeolite Beta and their interaction with probe molecules by DFT method. Some intresting results were obtained. These results will provide help for the readers in the field of acid catalysis. So, it can be accepted after revising the language. The authors should clarify what form of the sample, protoned or deprotoned?
Author Response
The reviewer wrote:
The manuscript studied the single Brønsted acid sites in zeolite Beta and their interaction with probe molecules by DFT method. Some intresting results were obtained. These results will provide help for the readers in the field of acid catalysis. So, it can be accepted after revising the language. The authors should clarify what form of the sample, protoned or deprotoned?
Reply:
Thank you for the comment. At first, we studied deprotonated samples with different locations of single Al atom in the model, measured their energy, then we studied protonated samples that have proton attached at all possible oxygen atoms around the Al sites. Thus, we computed energy of deprotonation in vacuum and then energy of adsorption of test molecules. Thus, protonated samples were used for adsorption study. This was added to the abstract.
Reviewer 3 Report
This article is devoted to the theoretical study of single Bronsted acid sites in beta zeolite and their interaction with probe molecules. The article is written in a clear and accessible language. The data obtained by the authors are not in doubt. There are some points that could be improved:
.1. The introduction can be extended.
2. It is necessary to provide justification for the choice of model (including the basis) for calculations.
3. It would be good if the obtained calculated data were compared with the experimental ones.
4. In addition, comparison of the obtained results with data from literature sources will also improve this work.
5. Conclusions need to be supplemented. Now they look too modest. This is strange, since the authors obtained interesting and new data in sufficient quantities.
6. It is desirable to more clearly indicate what is the novelty and perspective of this study.
Author Response
The reviewer wrote:
This article is devoted to the theoretical study of single Bronsted acid sites in beta zeolite and their interaction with probe molecules. The article is written in a clear and accessible language. The data obtained by the authors are not in doubt. There are some points that could be improved:
.1. The introduction can be extended.
Reply:
Thank you for the comments. The introduction has been extended.
The reviewer wrote:
- It is necessary to provide justification for the choice of model (including the basis) for calculations.
Reply:
The model was developed and tested previously in one of our studies. The newer basis sets and pseudopotential were used for the purposes of testing and comparison with the previous results.
The reviewer wrote:
- It would be good if the obtained calculated data were compared with the experimental ones.
Reply:
Comparison with experimental data and also with the computed data of other workers has been included in the manuscript.
The reviewer wrote:
- In addition, comparison of the obtained results with data from literature sources will also improve this work.
Reply:
We have made comparison of energy of adsorption for some of the molecules used with energy of adsorption of other authors. A good agreement was generally found.
The reviewer wrote:
- Conclusions need to be supplemented. Now they look too modest. This is strange, since the authors obtained interesting and new data in sufficient quantities.
Reply:
The conclusions were augmented and extended.
The reviewer wrote:
- It is desirable to more clearly indicate what is the novelty and perspective of this study.
Reply:
This work confirmed previous results on the absence of correlation of adsorption energy of test molecules with acid strength of acid sites in zeolites. The novel basis sets in CP2K was successfully tested and can be recommended for further use. The quality of multigrid is recommended to be not less than 5/600/50. The information was added to the conclusions.
