Electrochemically Fabricated NiW on a Cu Nanowire as a Highly Porous Non-Precious-Metal Cathode Catalyst for a Proton Exchange Membrane Water Electrolyzer

초록

A hierarchical Ni x W 100-x /Cu nanowire (NW) catalyst for the acidic hydrogen evolution reaction was electrochemically fabricated on carbon paper (CP) for practical applications of a proton exchange membrane water electrolyzer (PEMWE). The Ni and W contents in the catalysts were controlled by adjusting the concentration of Ni and W precursors during electrodeposition. The as-prepared catalyst had an amorphous structure due to the addition of W. The activities of Ni x W 100-x /Cu NW/CP catalysts were evaluated for hydrogen evolution. The Ni 96 W 4 /Cu NW/CP catalyst had the highest intrinsic activity among the catalysts with an overpotential of 56 mV at -10 mA cm -2 , whereas those of Ni 100 /Cu NW/CP and Ni 96 W 4 /Cu/CP were 177 and 77 mV, respectively. The performance improvement was attributed to the amorphous structure of NiW and the use of a large surface area of Cu NW as a porous sublayer. Finally, Ni 96 W 4 /Cu NW/CP was implemented as the cathode of a PEMWE which offered a performance that was ∼80% of that of a Pt-cathode-embedded electrolyzer and 320% of that of a non-Pt-cathode-embedded electrolyzer at 2.0 V cell , as reported in the recent literature. © 2019 American Chemical Society.

키워드