Boosting the Performance of Nano-Ni Catalysts by Palladium Doping in Flow Hydrogenation of Sulcatone

Round 1

Reviewer 1 Report

In this manuscript, the authors show that adding a slight amount of Pd to a Ni catalyst in a flow reactor environment can improve the hydrogenation of 6-methyl5-hepten2-one. The experimental results were confirmed with the support from density functional theory methods and isotope substitution. The experiments are carefully performed, and their results are very promising. However, before accepting the manuscript for publication, I would like the authors to perform the following to strengthen their claim.

1. In Table 1, they show clear kinetic isotope effects of over 1.7. The basic assumption here is that the concentration of H₂ from the electrolysis of H₂O is equivalent to the concentration of D₂ from the electrolysis of D₂O in their “plug-and-play” reactor. Can they provide proof of this?
2. In Table 2, the authors show a decrease in the H₂ dissociation barrier on the different clusters. Another important point concerning their experiment is the spillover of the dissociated H atom on Pd to the Ni surface. Can they also confirm by computations if the spillover process is also a low barrier process?
3. They showed results concerning NiPd0.05TSNH2 and NiPd0.13TSNH2. Can they perform further experiments with increased Pd concentration to find the optimum doping % of Pd? Also, how sensitive are the results to the pressure and flow rate of the reactor?

Minor things are

Table 1 is hard to understand since it contains information of two different variables so please put a vertical line after the second column. Also, for the first-row first-column, please put in the pressure of the experiment after “Temperature“, and for the first-row third-column please specify the temperature after “Gas Pressure”.   

Is there a particular reason that the kinetic isotope effect at 45 degrees Celsius shows differences compared to other temperatures?

Author Response

Please find the replies to comments in the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Ilona Goszewska and co-authors studied the “boosting Ni performance in α,β-unsaturated ketone  flow hydrogenation by Pd doping”. The work is interesting but the manuscript need major revision to show the originality of the obtained results. Particularly, organization of the results is poor and need more attention.

1. The first three lines of the abstract are not necessary.
2. To show the novelty of this work, only the major interesting results can be mentioned on the abstract, of course a comparison and some values are requested. Also it will be better to add the results obtained from the kinetic isotopic measurements and theoretical calculations.
3. Introduction is ok for me. Line 42 : product[15–18] ➙product [ 15-18];

line 73: ”plug-and-play”➙ ‶plug-and-play″

4. Results and discussion:

This part need organization. In its present form the article, seem to be a routine of other published work and the results are not well presented, so the authors should payed more attention about the coherence of the results and characterization. In addition it is hard to read this part without mentioning where are the results and the discussion.

I suggest two form of structure: 1) Results and then the discussions ; or 2) introduce a title for each characterization/discussion part.

Line 109: please rephrased the following sentence (Figure 2a insert shows the histogram Ni NPs size 110 estimated from about 100 particles)

5. Experimental section: the concentration of NaBH4 and trioctylophosphine oxide should be supplemented.
6. The FTIR characterization is interesting and must be moved from the supplementary file to the manuscript.
7. The conclusion is better than the abstract, both of them should be coherent.

Author Response

Please find the replies to comments in the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Now the revised manuscript is ready to be published in Catalysts journal.