A fuel cell-electrolyzer series device for simultaneous monoethanolamine degradation and hydrogen production: From anode screening and optimization to device investigation

A fuel cell-electrolyzer series device with monoethanolamine (MEA) as fuel in the fuel cell and MEA-containing electrolyte in the electrolyzer is developed. The fuel cell stack directly powers the electrolyzer. As a result, MEA is degraded electrochemically in the anode sides of both fuel cell and electrolyzer, while high value-added H2 is produced in the cathode side of electrolyzer with a little supplied power or even without any. This work firstly screens out Au as the best-performing electrocatalyst for MEA electrooxidation. Following this, Au?Ni bimetals coated on nickel foam (Au?Ni@Ni foam) are prepared by the facile electrodeposition. An Au?Ni@Ni foam electrode with the optimized electrodeposition time of 30 min exerts a considerable area current of 27.2 mA cm-2, Au mass current of 58.1 A g-1 and onset potential of -0.44 V vs. Ag/AgCl in 1.0 mol L-1 KOH and 0.05 mol L-1 MEA. The electrochemical tests companied with the physico-chemical characterizations elucidate the monometallic-state Au, rather than its alloy-state, benefits the MEA electrooxidation. Tests finally show such fuel cell-electrolyzer series device equipped with Au?Ni@Ni foam anodes operates well in bench scale, which accordingly proves the device to be a tenable and smart strategy for simultaneous MEA degradation and resource recovery.

Automated summary

A fuel cell-electrolyzer series device with MEA as fuel has been developed, and an Au?Ni@Ni foam anode prepared by optimized electrodeposition method shows excellent performance in MEA degradation and hydrogen production.