Effect of Modulation and Functionalization of UiO-66 Type MOFs on Their Surface Thermodynamic Properties and Lewis Acid–Base Behavior
, Thibault Roques-Carmes 5, Mohamad Hmadeh 3,* and Joumana Toufaily 1,2Round 1
Reviewer 1 Report
Degree C is not 0C or oc. the author should change all the symbols.
Why UiO-66-00 and UiO-66-AA were synthesized at different scales? The scale of reaction can also lead to differences in defects and should be avoided.
There is font inconsistency in the manuscript.
The PXRD pattern collected does not include the low-angle data which can directly show the existence of defects at 4 and 6 degrees.
In figure 4, the final weight of 1 and 3 did not reach a steady weight. This can cause issues with the missing linker calculation. Can the author also explain why a non-modulated MOF is showing fewer defects than the modulated specie?
Author Response
Please see attachment
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Ali-Ali Ahmad and co-workers report the synthesis of 4 different analogues of UiO-66 based on the utilization of different modulators as well as on an amine functionalized linker. All the synthesized MOFs are characterized using state of the art techniques as PXRD, SEM, N2 sorption and TGA. Also, the importance of the modulator used in the number of defects is examined and discussed. Furthermore, the aforementioned MOFs are studied regarding their thermodynamic and surface properties as well as their Lewis acid/base nature using the technique of IGC at infinite dilution. The manuscript is clearly written, the claims are supported by the experiments conducted and the appropriate literature citations are present. Thus, this article can be published in catalysis after the following revisions and suggestions.
· Line 70: The authors are commenting on the effect of different modulators in the porosity of Zr based MOFs adopting the topology of UiO-66. I believe they should also include in their citations “ Pantelis Xydias, Ioannis Spanopoulos, Emmanuel Klontzas, George E. Froudakis, and Pantelis N. Trikalitis, Inorganic Chemistry 2014, 53, 2, 679-681” which is also presenting the effect of diverse modulators in the uptake capacity of MOFs of the same family.
· Line 92: The authors state that the main purpose of ligand functionalization is to modify the properties of the material for a desired application. However, different recent studies have also revealed that the functionalization of the linker can be a crucial factor determining the topology of the resulting net, considering its effect on the ligand conformation. I believe that it would be informative for the readers to add a comment regarding the subject.
· As it is described, the authors chose DCM as a volatile solvent in order to exchange DMF from the pores of the MOF in order to activate it. A) What led them to the choice of the certain solvent? B) Have they tried different solvents? C) Is the material stable in this solvent (perhaps a PXRD pattern od the sample after its immersion in the solvent could be helpful) D) How the authors verified that DCM managed to successfully remove DMF, perhaps an 1H-NMR spectrum presenting the absence of DMF could be helpful
· Considering that the presence of DMF in the pores of the material can affect the results of the rest of the measurements, have the authors verified after the heating of the MOF, the complete removal of the solvent. 1H-NMR of the material after degassing could be useful.
· Although the authors provide us with detailed gas sorption measurements of N2 at 77K for each synthesized MOF along with its BET surface area. I believe that also a calculation of the pore size distribution of each material would better describe the porosity of the materials. Also, regarding the BET calculations, I suggest that the authors also provide the readers with the relevant graphs from which the calculation occurred along with the corresponding R values.
· A small step is recorded in the sorption isotherm of UiO-66-FA MOF. Do the authors have a comment regarding it? Why is it present only in the FA analogue?
· Do the authors have a comment correlating their findings of the acid or basic nature of the examined MOFs regarding their potential application in specific catalytic reactions? A small paragraph in the conclusion part I think would enrich the article.
Author Response
Please see attachment
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The authors have provided answers to all the comments made. After these revisions I believe that their manuscript is suitable for publishing.
