Dimitris N. Chorafas Foundation Award - 2022 - Weiyan Ni
The design and synthesis of nanostructured hydrogen oxidation reaction electrocatalysts for hydroxide exchange membrane fuel cells
Thesis director: Prof. X. Hu
For his original, innovative contributions to the development of non-precious anode catalysts for the anion exchange membrane fuel cells.
Hydroxide exchange membrane fuel cell (HEMFC) is an emerging green technology that transforms the chemical energy in hydrogen into electricity in alkaline media. Currently, the lack of active and stable earth-abundant catalyst for the hydrogen oxidation reaction (HOR) at the anode is a major barrier to the progress of HEMFC. In this thesis, we developed Ni-based HOR catalysts that have significant improvement in terms of both catalytic activity and stability, and interpreted their performance by constructing structure-activity relationships. We first identified Ni3N as a new HOR catalyst with higher activity and a wider electrochemical window than metallic nickel. We then showcased that the strain engineering is a promising strategy to tune the catalytic activity of nickel nanoparticles. Finally, we developed a nickel catalyst with high HOR activity. When coupling with a CoMn-based cathode, the resulting hydrogen fuel cell delivered a 488 mW/cm2 peak power density, which is more than 6 times higher than the previous best performing analogues. This work demonstrated the feasibility of efficient earth-abundant HEMFCs.