Rh-WO3 Electrocatalyst for Hydrogen Evolution Reaction in the Alkaline Seawater Electrolyte

One potential strategy to develop hydrogen evolution electrocatalysts for producing sustainable hydrogen in water electrolysis is creating electrocatalysts with low-cost, high activity, and high stability. Herein, we show that low-loading metal-based tungsten oxide (WO3) can be used as electrocatalysts for the hydrogen evolution reaction (HER) in acid, alkaline, and alkaline seawater electrolytes. Among prepared electrocatalysts, rhodium (Rh)-WO3 exhibits a high HER activity with the values of overpotential of 48, 116, and 98 mV to obtain a current density of 10 mA.cm-2 in acid, alkaline, and alkaline seawater electrolytes, respectively. In addition, the Rh-WO3 electrocatalyst shows high stability during the HER operation for over 60,000s. Besides, the application of Rh-WO3 electrocatalyst as cathode and commercial ruthenium oxide (RuO2) as an anode for overall water splitting show excellent efficiency with only a potential of 1.45 V to a current density of 10 mA.cm-2 in the alkaline-seawater electrolyte. The Rh-WO3//RuO2 cell also exhibits high stability for over 40,000s. The results provide evidence that Rh-WO3 can be a promising HER catalyst for sustainable hydrogen production via alkaline-seawater electrolysis application, as show in Figure 1. Figure 1