Robust water/seawater-electrolysis hydrogen production at industrial-scale current densities by modulating built-in-outer electric field of catalytic substance

Abstract

Water/seawater-electrolysis hydrogen generation at industrially relevant rates is economically appealing but remains challenging due to the low activity and long-term stability of catalysts. To address these challenges, by means of the work function theory, we conceive a highly dispersed PdRu five-fold twinned structure supported on amorphous Fe (Cu) oxide (PdRu@MO_x, M=Fe or Cu), which has a strong built-in-outer electric field between heterointerfaces and five-fold local symmetry breaking. This results in an optimized interface charge density, improving proton adsorption and kinetics of the hydrogen evolution reaction (HER) at PdRu sites. Consequently, in alkaline electrolysis, PdRu@FeO_x requires overpotentials as low as 27 and 110 mV to achieve current densities of 100 and 1000 mA cm⁻², respectively, with exceptional catalytic stability for up to 10,000 cycles. Moreover, in alkaline seawater, only a 120 mV overpotential is needed to afford a large current density of 1000 mA cm⁻². Notably, the mass activity of PdRu@MO_x is 17 and 30 times higher than that of commercial Pt/C catalysts in alkaline water and seawater, respectively. This work will be broadly applicable for designing stable multi-metal-site catalytic substances, opening new possibilities for overall seawater electrolysis at industrial-scale current densities.