One-Pot Conversion of Furfural to γ-Valerolactone over Co- and Pt-Doped ZSM-5 Catalysts

Round 1

Reviewer 1 Report

The paper describes the investigation of ZSM-5 supported Pt and Co catalysts for furfural hydrogenation to GVL. Before being accepted for publication the following issues should be improved:

(1) Reactor and reaction conditions should be better described. What was the H2/ furfural ratio? Pressure was constant or there was pressure variatio during the reaction? H2 was continuiously flowed to reactor or not?

(2) Mass and heat transfer issues should be described.

(3) Reaction rates and turnover frequencies should be estimated.

Author Response

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Reviewer 2 Report

In this work, one-pot conversion of furfural to GVL product was investigated using Co- and Pt-doped ZSM-5 catalysts under mild reaction conditions. The monometallic Co/ZSM-5 and Pt/ZSM-5 were prepared by incipient wetness impregnation method. The catalysts were characterized by various techniques such as BET, XRD, NH3-TPD and in-situ FTIR spectra of pyridine adsorption. The catalysts functionalities were derived and correlated with their activity. The article is written correctly in terms of content as well as research. Each of the presented parts of the article was developed and presented in a correct way. The entire work is coherent, and closely related to all parts.  The conclusions are consistent and closely related to the research topic. As a reviewer, I have one question:

Is it possible to affect the life of the catalyst, if so, how. Have such studies been conducted? How many times can one catalyst be used in a process. How are the product yields in such a situation?

Author Response

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Reviewer 3 Report

1.       "Hemicellulose" is not suggested to be a keyword as it is not closely related to the content of this manuscript.

2.       The description of the catalyst preparation in section 2.1 should be more detailed, so the readers can repeat the experiments.

3.       The quantitative analysis method of the products should be shown in Section 2.3. Was it area normalization method? As there were some polymers by-products in this reaction which couldn’t be detected in GC, selectivity and yield of the products may be not correct. External standard method or Internal standard method is suggested to be used.

4.       Fig. 4. depicted a possible reaction network scheme for the one-pot conversion of furfural to GVL over the bifunctional Lewis/Brønsted acid catalysts. But the catalyst was reduced with hydrogen at 500ºC for 2 h. Was the reduction of furfural in this reaction catalyzed by Lewis/Brønsted acid or metal active sites? In conclusion, the authors came to the conclusion “The appropriate acid properties and metal-catalyzed path way facilitated MPV reduction of furfural to γ -Valerolactone (GVL)”.  The 1%Pt/ ZSM-5 catalyst reduced with hydrogen should be characterized. The role of metal, L/B acid active sites of the 1%Pt/ ZSM-5 should be clearly studied. And Fig. 4. may need to be modified.

5.       What about the reusability of the 1%Pt/ ZSM-5?

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Paper may be published now