Porosity and Structure of Hierarchically Porous Ni/Al2O3 Catalysts for CO2 Methanation
, Ken L. Abel 3, Ronny T. Zimmermann 4, Xiaohui Huang 5,6, Jens Bremer 7, Liisa K. Rihko-Struckmann 7, Darren Batey 8, Silvia Cipiccia 8, Juliane Titus 3, David Poppitz 3, Christian Kübel 5,6,9, Kai Sundmacher 4,7, Roger Gläser 3 and Thomas L. Sheppard 1,2,*Round 1
Reviewer 1 Report
In this study, Weber et al. assessed the utilization of a hierarchical Ni/Al2O3 home-made catalyst on CO2 hydrogenation to methane. The work was mainlly devoted to the characterization of the pore structure of the investigated sample. The manuscript is well-written and characterization results are discussed in details. However, in order to be accepted for publication, the following point should be addressed:
1) In order to demonstrate the superiority of the hierarchical structure, the sample named Ni/Al2O3-m should be used as a benchmark for results shown in Figure 2, Figure 3, Figure 4, Figure 5, and Figure 6. In particular, catalytic tests should be discussed at the light of catalytic behaviour of Ni/Al2O3-m sample.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
#1: Catalytic reaction data for Ni/Al2O3-m
The information of Ni/Al2O3-m is too fragmentary despite being important reference because of only possessing the mesopore. For instance, section 2.3 (Tomography Studies), 2.4 (Porosity Analysis), 2.5 (Macrokinetics) give perfect discussion by quantitative comparison between Ni/Al2O3-h and Ni/Al2O3-m, whereas section 2.2 (Catalytic Measurements) has a lack of essential reference information.
I strongly request to add catalytic data of Ni/Al2O3-m into Figure 4, which enable us to direct comparison between experiment (Section 2.2) and multi-scale simulation (Section 2.5) results, giving important evidence to emphasize this excellent work.
#2: significant figures in Table 2
The reviewer cannot understand the scientific meaning about the large significant figures for Vs, tot, and Vp,tot in Table 2.
Author Response
Please see attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
No comment, the revision version of the manuscript is suitable for publication. I thank the authors for the detailed answer.
