Catalytic Materials by 3D Printing: A Mini Review
Round 1
Reviewer 1 Report
Dear Lina Shen;
After a careful revision of your manuscript entitled: "3D Printed Catalysts-a Mini Review", submitted to MDPI Catalyst. Although, the tridimensional printing and cases of study applied to catalytic materials is relative new trending topic in the field of nanomaterials. In order to improve the quality of your manuscript, I´m providing you strong suggestions that I personally consider needs to be taken into account.
1) Title needs to be changed, perhaps: "Catalytic Materials by 3D Printing: A mini-review"
2) Abstract also needs to describe the "core" content of the manuscript, in other words: Why doesn´t mention what type of catalyst have been printed and type of chemical reaction target to evaluate the performance. If it is clearly stated on the document the Ceria Oxides and Copper catalytic materials.
3) Typo in section 3.3 it says: "D printing for catalyst"
4) Authors state: "Further, 3D printing technology also enables free doping by simply adding the doping sources into the printing paste.49" Well, this is a very vague statement, authors should indicate the concentrations of dopants, how those enhance the electronic character and enhance catalytic activity, otherwise, dopants in large amounts can be considered contaminants that affect drastically catalytic performance. (See: Ramos et al. Catal. Sci. Technol., 2012, 2, 164–178).
5) Overall images are very blurry, perhaps to revise how those were obtained. Some of them also, can be redone. And a legend indicating: "Image taken from John Doe et al. with rights and permits of Editorial"
6) Authors indicate: "In addition to the structure design, preparation of printable inks is a critical step. In this work, the researchers firstly impregnated nickel nitrate salt onto alumina powders, and the theoretical content of nickel can be controlled in this step. After complete mixing, drying and ball milling processes, the mixture was calcined at high temperature to be transformed into Ni/gamma-Al2O3." My since apologies, but the complete sentence can be re-write to make more comprehensive to the reader.
Perhaps:
Precursor materials that involves catalyst preparation play an important role towards of design of 3D catalytic structure. Some authors, indicate usage of impregnation method using nickel nitrate salts onto alumina powders allowing to control mixture percentages, follow by calcination at elevated temperatures (Indicate the value) in order to transform into Ni/gamma-Al2O3 material. [If is powder material, then to indicate that]
7) Another important sentence that needs to be improved is:
"...loading of active catalysts onto 3D porous supports has been proved to be a good choice."
That sounds very colloquial English!, I believe needs to be improved.
8) Authors indicate: "There’s a lack of deep understanding for the relationship between structure and performance. It takes much time to try various structures fabrication and then unearth the best performance and explore the influence law". Well, I believe is because authors didn´t present much information about characterization, there is more than 100 manuscripts published and reports on the literature about characterization made by TEM, SEM, XRD and Atom Probe Tomography. Thus, authors need to search for that information that is available on the archives.
Author Response
We would like to begin by conveying our sincere appreciation for all the valuable comments, insightful suggestions and thoughtful corrections offered by the reviewers to our manuscript. Taking into consideration of these comments, we have revised the manuscript in which major changes are highlighted in red. These changes are summarized below following a point-by-point response to the Referee’s comments.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Dear Authors,
After carefully reading your manuscript entitled: " 3D Printed Catalysts-a Mini-Review", I would share my overall impression.
Firstly: The work is organized well and can be useful in the case of a literature search for other scientists, but in my opinion, in the short review, there should be attached some tables with state-of-the-art articles on this particular topic.
Catalysis is such a wide expression - which type of catalytic reaction are dedicated for? Are you writing about organic reactions? Hydrogen evolution process? The article has to be focused on some selected reactions because each of them has different requirements due to the conditions for example high temperature.
For this moment this article is about 3D printed materials for everything, so it missed from my point of view the idea connected with the review article (especially the short one).
I do not recommend this manuscript for publication in the state at this moment.
Best regards
Author Response
We would like to begin by conveying our sincere appreciation for all the valuable comments, insightful suggestions and thoughtful corrections offered by the reviewers to our manuscript. Taking into consideration of these comments, we have revised the manuscript in which major changes are highlighted in red. These changes are summarized below following a point-by-point response to the Referee’s comments.
Reviewer 3 Report
In this manuscript, authors expalined about three-dimensional (3D) catalysts monoliths. However, few points should be considered before publication.
Need to use proper words through entire manuscript like in "construction of three-dimensional (3D) catalysts monoliths" the word construction is not vey fiitted.
need to mention more keywords.
please make sure that if any figure was taken from third party then should take permission.
need to incorporate atleast one table to show/comparison some previous work.
Author Response
We would like to begin by conveying our sincere appreciation for all the valuable comments, insightful suggestions and thoughtful corrections offered by the reviewers to our manuscript. Taking into consideration of these comments, we have revised the manuscript in which major changes are highlighted in red. These changes are summarized below following a point-by-point response to the Referee’s comments.
Round 2
Reviewer 1 Report
Dear Authors;
After a careful revision of your manuscript with control ID: Catalyst-1833158 and based on the improvements made to the original version. I believe the manuscript is ready to be accepted for publication in the journal. However, this would be a decision of the editorial house.
The manuscript and can serve to inspire young graduate and undergraduate students to explore other fields in this particular case the 3D-printing world into catalytic materials.
Reviewer 2 Report
Dear Authors,
I read the corrected version of the manuscript, and still, it is a general article about 3D-printed techniques in catalysis. There are visible differences between previously-submitted and current versions in terms of narrowing the topic to a specific catalytic reaction/process type. I expected to see something closer to this review article: "Combining additive manufacturing and catalysis: a review" - https://0-doi-org.brum.beds.ac.uk/10.1039/C7CY00615B, or: "3D printing in chemical engineering and catalytic technology: structured catalysts, mixers and reactors" - OPEN ACCESS. https://0-pubs-rsc-org.brum.beds.ac.uk/en/content/articlehtml/2018/cs/c7cs00631d.
Where the authors arbitrary select one or two catalytic processes and briefly explain and underline the achievements of 3D printed materials in these very narrow particular reactions.
As I stated before, this manuscript is too general, and the authors must underline the demand for this type of article. Via the Scopus database, we can easily find the much more focused and detailed review articles connected with the application of 3D printed materials in catalysis (many different catalytic processes).
Based on these statements, I do not recommend it for publication.
