Amorphous Fe-Co oxide as an active and durable bifunctional catalyst for the urea-assisted H 2 evolution reaction in seawater.

In this study, we prepared amorphous iron-cobalt oxide through the dealloying of trimetallic FeCoAl, showing excellent performance in both urea oxidation and hydrogen evolution reactions (UOR and HER) in alkaline seawater. The catalyst demonstrated stable UOR and HER activity during long-term operations due to the abundant active sites and oxygen vacancies. The catalyst required applied potentials of 1.52 and -0.185 V to yield 100 mA cm -2 for the UOR and HER, respectively. Moreover, when used as both the cathode and anode, the electrolyzer required a working voltage of 1.68 V to yield 100 mA cm -2 for urea-assisted hydrogen production.