Electrodeposition of a Li-Al Layered Double Hydroxide (LDH) on a Ball-like Aluminum Lathe Waste Strips in Structured Catalytic Applications: Preparation and Characterization of Ni-Based LDH Catalysts for Hydrogen Evolution
Round 1
Reviewer 1 Report
The manuscript is well written and the authors performed original research emphasizing the possibility to valorize aluminum lathe waste strips and converting those into Li-Al-LDH supports for catalytic materials (with Ni active phase) for ethanol steam reduction. The authors use a wide range of analytical techniques for the characterization of their catalysts and the results are correlated with those obtained in catalytic activity tests. I disagree only with one aspect of their characterization techniques, namely the characterization of the solids by the temperature-programmed desorption of NH3. Even if numerous other authors apply this technique in the temperature range 50-600oC, this approach is theoretically not accurate since beyond 500° C, NH3 starts to decompose and the obtained profile does not reflect the reality anymore. Another aspect that would require the attention of the authors would be the determination of the base sites of the catalysts since Li-Al-CO3 is known to belong the the class of LDH anionic clays which are more basic than acid. The determination of both acid and base sites of the catalysts and the ratio between acidity/basicity could bring more value to the results discussed by the authors.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
In my opinion, the article is logically structured. Attention is drawn to the number of methods by which the material was studied, which, to a certain extent, reflects the quality and reliability of the results. The interpretation of the analytical data is consistent with published data. The topic is in demand and fits the theme of the journal. I have only minor comments, which are listed below.
The article looks ready for publication, but in my opinion it is longer than it could be. For example, the text describes what is shown in the figures. I think these parts could be more concise.
line 155 NaCl2 (!?)
Figure S1 is unvailable in my version
line 166 "The two samples NaOH and NaHCO3 yield the same diffrac-165 tion peaks’ 2theta positions..." - it is necessary to provide exact values rather than qualify them as "the same position".
Figure 3: pahse B has wide and low-intensive reflections, while pahse A on opposite. So, the indexing of the most intesive reflection as A and B looks weird, it seems to be reflection of the A phase.
line 286 "narrowband" - add space/
Figure 8 - it is not clear what phases do you attribute to what contrast?
lines 415-416: "FWHM 415 (full width at half maximum) than the FWHM of the strong peaks of the Ni(OH)2" - Provide values of FWHM.
line 435 "structural model" - usually this term is refered to a model where atomic coordinates were determined. It does not sound correct here. Or give expalantion structural model of (what?) IS dispalyed.
Line 546 "The molar ratio of Li+ to Al3+ ions in the electrolyte solution 546
was two" should it be The molar ratio Li:Al = 1:2(?).
I also noticed that you use the past form "was" instead of "is". Double check the manuscript.
line 629 "NaCl2" (!?).
line 630 in situ - italic.
lines 633-634 "However, the Ni content using the NaOH titration had about 633 two times higher than NaHCO3 titration, suggesting had two times of the Ni precursors" - the words in the sentence do not match.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The authors improved their manuscript and answered to my comments. However when they had cut parts of the text and reformulate some sentences they made some mistakes in English language usage. Please consider revising the text.
