High-performance hydrogen evolution reaction (HER) catalysts are compelling for the conversion of renewable electricity to fuels and feedstocks. The best HER catalysts rely on the use of platinum and show the highest performance in acidic media. Efficient HER catalysts based on inexpensive and Earth-abundant elements that operate in neutral (hence biocompatible) media could enable low-cost direct seawater splitting and the realization of bio-upgraded chemical fuels. In the challenging neutral-pH environment, water splitting is a multistep reaction. Here we present a HER catalyst comprising Ni and CrO_x sites doped onto a Cu surface that operates efficiently in neutral media. The Ni and CrO_x sites have strong binding energies for hydrogen and hydroxyl groups, respectively, which accelerates water dissociation, whereas the Cu has a weak hydrogen binding energy, promoting hydride coupling. The resulting catalyst exhibits a 48 mV overpotential at a current density of 10 mA cm⁻² in a pH 7 buffer electrolyte. These findings suggest design principles for inexpensive, efficient and biocompatible catalytic systems.

高性能氢析出反应（HER）催化剂对于将可再生电力转化为燃料和原料非常有吸引力。最好的HER催化剂依赖于铂的使用，在酸性介质中表现出最高的性能。在中性（因此具有生物相容性）介质中运行的，基于廉价且富含地球的元素的高效HER催化剂可以实现低成本的直接海水分离，并实现生物升级的化学燃料。在具有挑战性的中性pH环境中，水分解是一个多步反应。在这里，我们介绍了一种HER催化剂，该催化剂包含掺杂在Cu表面上的Ni和CrO _x部位，该催化剂在中性介质中有效运行。Ni和CrO _x这些位点分别具有较强的氢和羟基结合能，从而加速了水的离解，而铜的氢结合能弱，从而促进了氢化物偶联。所得催化剂在pH 7缓冲电解质中在电流密度为10 mA cm ^-2时表现出48 mV的超电势。这些发现提出了廉价，有效和生物相容性催化系统的设计原理。