Direct-Hydrocarbon Proton-Conducting Solid Oxide Fuel Cells

Round 1

Reviewer 1 Report

Although the scope is somewhat insufficient for a review paper, it contains quite the latest research trends well.

There is no special comment on the contents described in this paper.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

This short review article from Liu and Duan focuses on the developments on the direct hydrocarbon proton-conducting solid oxide fuel cells (P-SOFC). The authors give a brief introduction coking and sulfur tolerance of the P-SOFCs and try to draw our attention to its advantages compared to conventional SOFCs. I found a lack of debate as to whether the current experimental results really support this coking and sulfur tolerance of P-SOFCs (see my comment #4). In general, it is well written, and I can suggest it to be published in the journal “Sustainability”. However, there are a few issues to be addressed:

1. Line 161: The next 3 sentences seem to be forgotten to be deleted?
2. Line 169: please provide a reference to the advantages of P-SOFCs listed.
3. Line 190: Another reference is necessary for to the following text: “However, the experimental studies of P-SOFCs contradicts the thermodynamic predictions, which is due to unique surface properties of proton-conducting oxides.”
4. Under section 5, it would be great to have a table listing the materials, specific conditions for the experiments e.g., fuel, current density, temperature of operation, stability results etc. This would be particularly interesting to the readers as the authors later comment on the lack “of chemical stability under more realistic working conditions, such as fuel streams containing high-concentration impurities (CO2, NOx, and H2S)”. Bringing back my comment above, this table would provide a list of experimental conditions reported in the literature so far and point to where we are in terms of ‘benchmark’ conditions.

Author Response

Please see the attachment

Author Response File: Author Response.pdf