In the scale-up of water electrolysis,commercial systems require catalysts that are effective,stable,and earth-abundant.Although platinum group metal(PGM)catalysts exhibit remarkable activity,the high cost and scarcit...In the scale-up of water electrolysis,commercial systems require catalysts that are effective,stable,and earth-abundant.Although platinum group metal(PGM)catalysts exhibit remarkable activity,the high cost and scarcity significantly increase the overall capital expenses for alkaline water oxidation[1].As a more sustainable alternative,non-PGM catalysts—particularly first-row(3d)transitionmetal(oxy)hydroxides—show great promise for water oxidation.However,from a theoretical standpoint(e.g.,Pourbaix diagrams)[2],these active phases are often difficult to detect compared to PGM under oxygen evolution reaction(OER)conditions,underscoring the need to stabilize them during operation.Moreover,the rapid degradation of these metal(oxy)hydroxides is potential-dependent and typically occurs at high overpotentials required to achieve practical current densities,often associated with the dissolution of catalytic metal sites or phase segregation under harsh OER conditions[3].Together,these factors present a critical challenge in the development of metal(oxy)hydroxide catalysts—namely,stabilizing both the active phases and active sites,particularly during long-term operations at high current densities[4].展开更多
文摘In the scale-up of water electrolysis,commercial systems require catalysts that are effective,stable,and earth-abundant.Although platinum group metal(PGM)catalysts exhibit remarkable activity,the high cost and scarcity significantly increase the overall capital expenses for alkaline water oxidation[1].As a more sustainable alternative,non-PGM catalysts—particularly first-row(3d)transitionmetal(oxy)hydroxides—show great promise for water oxidation.However,from a theoretical standpoint(e.g.,Pourbaix diagrams)[2],these active phases are often difficult to detect compared to PGM under oxygen evolution reaction(OER)conditions,underscoring the need to stabilize them during operation.Moreover,the rapid degradation of these metal(oxy)hydroxides is potential-dependent and typically occurs at high overpotentials required to achieve practical current densities,often associated with the dissolution of catalytic metal sites or phase segregation under harsh OER conditions[3].Together,these factors present a critical challenge in the development of metal(oxy)hydroxide catalysts—namely,stabilizing both the active phases and active sites,particularly during long-term operations at high current densities[4].
