TY - JOUR
T1 - Elucidation of oxygen reduction reaction and nanostructure of platinum-loaded graphene mesosponge for polymer electrolyte fuel cell electrocatalyst
AU - Ohma, Atsushi
AU - Furuya, Yoshihisa
AU - Mashio, Tetsuya
AU - Ito, Masashi
AU - Nomura, Keita
AU - Nagao, Tomohiko
AU - Nishihara, Hirotomo
AU - Jinnai, Hiroshi
AU - Kyotani, Takashi
N1 - Funding Information:
Authors would like to acknowledge Dr. Takeshi Higuchi for the experimental support of 3D-TEM tomography and image processing, and fruitful discussion. This work was partially supported by “Five-star Alliance”.
Publisher Copyright:
© 2021
PY - 2021/2/20
Y1 - 2021/2/20
N2 - A graphene mesosponge (GMS), which has a sponge-like mesoporous framework, was applied to a catalyst support for polymer electrolyte fuel cell. Platinum loaded GMS (Pt/GMS) was prepared as electrocatalyst for oxygen reduction reaction (ORR) measurement and compared with platinum loaded Ketjen black (Pt/KB). ORR activity was evaluated by rotating ring disk electrode (RRDE) method to analyze hydrogen peroxide (H2O2) evolution behavior as an indicator of ionomer coverage on Pt. It was found that the ORR area specific activity of Pt/GMS was 1.2 times higher than that of Pt/KB with less H2O2 yield, mainly attributed to the lower ionomer coverage at Pt/GMS. It was also observed by transmission electron microtomography (3D-TEM) that Pt/GMS has a lot of pores between the sponge-like mesoporous framework with Pt nanoparticles therein. On the other hand, Pt/KB showed smoother agglomerate shapes with Pt nanoparticles inside the KB agglomerates mainly. Considering the frame-like mesoporous carbon network having hydrophobic basal nanosurface of the graphene of GMS and the aqueous electrolyte in this system, it is concluded that the ionomer can form self-aggregation with its hydrophobic domain inside, resulting in ineffective coverage of the ionomer on the nanostructure of GMS and the Pt nanoparticles in the GMS agglomerates.
AB - A graphene mesosponge (GMS), which has a sponge-like mesoporous framework, was applied to a catalyst support for polymer electrolyte fuel cell. Platinum loaded GMS (Pt/GMS) was prepared as electrocatalyst for oxygen reduction reaction (ORR) measurement and compared with platinum loaded Ketjen black (Pt/KB). ORR activity was evaluated by rotating ring disk electrode (RRDE) method to analyze hydrogen peroxide (H2O2) evolution behavior as an indicator of ionomer coverage on Pt. It was found that the ORR area specific activity of Pt/GMS was 1.2 times higher than that of Pt/KB with less H2O2 yield, mainly attributed to the lower ionomer coverage at Pt/GMS. It was also observed by transmission electron microtomography (3D-TEM) that Pt/GMS has a lot of pores between the sponge-like mesoporous framework with Pt nanoparticles therein. On the other hand, Pt/KB showed smoother agglomerate shapes with Pt nanoparticles inside the KB agglomerates mainly. Considering the frame-like mesoporous carbon network having hydrophobic basal nanosurface of the graphene of GMS and the aqueous electrolyte in this system, it is concluded that the ionomer can form self-aggregation with its hydrophobic domain inside, resulting in ineffective coverage of the ionomer on the nanostructure of GMS and the Pt nanoparticles in the GMS agglomerates.
KW - Graphene mesosponge (GMS)
KW - Ionomer coverage
KW - Oxygen reduction reaction (ORR)
KW - Polymer electrolyte fuel cell (PEFC)
KW - Transmission electron microtomography (TEM)
UR - http://www.scopus.com/inward/record.url?scp=85100218857&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85100218857&partnerID=8YFLogxK
U2 - 10.1016/j.electacta.2020.137705
DO - 10.1016/j.electacta.2020.137705
M3 - Article
AN - SCOPUS:85100218857
SN - 0013-4686
VL - 370
JO - Electrochimica Acta
JF - Electrochimica Acta
M1 - 137705
ER -