Trimeric Ruthenium Cluster-Derived Ru Nanoparticles Dispersed in MIL-101(Cr) for Catalytic Transfer Hydrogenation
Round 1
Reviewer 1 Report
The manuscript entitled with “Trimeric Ruthenium Cluster Derived Ru Nanoparticles Dis-2 persed in MIL-101(Cr) for Catalytic Transfer Hydrogenation” discusses the Ru nanoparticles supported MIL-101(Cr) catalyst for the transfer hydrogenation of benzene using 18 isopropanol as the hydrogen source. The investigations are interesting and with the overall impact of what is presented being more than sufficient for publication in Catalysts. I recommend acceptance of this manuscript and have some remarks which will improve the quality of the manuscript:
1. The authors should provide the design idea of Ru nanoparticles supported MIL-101(Cr) catalyst in the introduction, it is important to preview the design of more interesting catalysts under stimulation.
2. The results of catalytic performances should be compared with other related works to prove the advantages of titled design catalysts.
3. As the catalysts, the chemical stability of designed materials must be considered. Thus, PXRD or other tests should be added to illustrate this.
4. MOFs as well as their catalytic properties have been largely previous reported in literatures, to arouse a broad interest from the readership, several previous works in this field can be enriched, such as Mater. Today Chem., 2022, 24, 100984, Inorg. Chem., 2022, 61, 11949.
5. There are few grammar mistakes in this manuscript, the English of the manuscript should be further improved.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
In this interesting work, Kyung-Ryul Oh and co-authors report about preparation and testing of the hybrid catalytic materials with Ru-nanoparticles deposited onto MIL-101(Cr) supporting material and aimed for transfer hydrogenation of benzene. The materials are clear presented and methods used are appropriate and robust. On the other side, there are several points (listed below) presents that should be cleared out before the manuscript can be accepted for publication in Catalysts journal.
1) In the main discussion, the authors say that
“In pore size distribution plots (Figure 1d), the pore volume at 2–3 nm of MIL-101(Cr) was reduced after the grafting of ED and Ru3 clusters”
but at the microphotographs (Figure 2) there are no any pores of such diameter can be observed. Please comment.
2) From Scheme 1 it is clear that the effective diameter of Ru3 complex is quite high, and such molecules can not penetrate through the windows of MIL-101(Cr) structure. Therefore, it is more realistic to discuss the deposition of Ru3 complexes as a sorption at the surface of MIL-101 particles.
As a supplement, I would like to note for authors that despite the high N2 BET values are well documented for MIL-101 and other MOF, the parameters of chemosorption of coordination compounds by such materials from a solution is much more rear information. For example, such information (sorption isotherms or kinetic curves for sorption of Ru3 by ED-MIL-101(Cr)) if presented for discussed combination (ED-MIL-101(Cr) + ethanol solution of Ru3 complex) would sufficiently strength the work and provide information on possibility to control the content of Ru in the resulting materials.
3) For the sake of clarity, the method used for dissolution of materials prior to analysis should by described.
4) Authors describe the mode of Ru3 complex binding as the formation of coordination bond with N-center of grafted ethylenediamine, but there are other possibilities including physical sorption or ion-paring interaction between protonated -NH3+ groups of ED and deprotonated form of Ru3 complex. For example, in the cited work [16] just the noted ion-pairing interaction (-NH3+…[PdCl4]2-) was postulated for related materials ED-MIL101 materials. This mechanism also can lead to analogous changes in IR spectra as discussed in the manuscript (reduced intensity with a slight shift of the N–H peaks). Authors should at least comment on this situation and support their point of view with experimental evidences.
5) line 94 “…contains 2.8 wt% of nitrogen content…” please correct.
6) For greater informativity I recommend including full formula of Ru3 complex in Abstract because it does not appear in main discussion and is only described in Materials and Methods section.
7) A reference for the original synthesis procedure (which was modified) for Ru3 complex should be added in Experimental section.
Author Response
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Author Response File: Author Response.pdf
