Rational design of integrated electrodes for advancing high-rate alkaline electrolytic hydrogen production

Abstract

The goal of global carbon peak and neutrality calls for the green production of hydrogen via water electrolysis powered by renewables. Alkaline electrolysis cells (AEC) are receiving more attention since they can economically produce hydrogen at a large scale without the need for expensive catalysts. Developing advanced integrated electrodes from earth-abundant materials is crucial for driving this technique, however they suffer from poor catalytic activity and durability under industrial current densities. This review herein focuses on the rational design of integrated electrodes to advance alkaline electrocatalytic hydrogen production (AEHP). The representative strategies are first introduced, including modulating the electronic structure and harnessing the synergy from multi-components for improving activity as well as constructing the tri-phase interfaces with appropriate surface hydrophilic/aerophobic properties. For cost-competitive hydrogen production, the cost-effective scalable production of such integrated electrodes is discussed, which should be simultaneously considered when improving the electrode performance. Moreover, such integrated electrodes could be applied to the emerging water electrolysis systems such as anode-replacing hydrogen production and decoupled AEC for boosting AEHP. Finally, the review provides an outlook of the remaining challenges and emerging research topics in the future, including the standard evaluation of catalytic performance, precise identification of genuine catalytic sites at working conditions, accurate theoretical modeling and AI-assisted catalyst screening, and external-fields coupled AEC, etc. The new insights and knowledge provided regarding these aspects will help fill the existing gaps between scientific communities and industries and open up opportunities for bringing this promising technology into reality.