A review of transition-metal boride/phosphide-based materials for catalytic hydrogen generation from hydrolysis of boron-hydrides

Abstract

Efficient hydrogen generation and storage is an essential prerequisite of a future hydrogen economy. Boron hydrides feature high volumetric density and high hydrogen generation, making them a promising candidate for chemical hydrogen storage. The development of efficient non-noble metal catalysts for on-demand hydrogen release through boron-hydride hydrolysis under mild conditions has received extensive interest. Transition-metal boride/phosphide based materials are attractive due to their advantages of earth-abundant elements, considerable catalytic activity, high stability and low cost. In this review, we summarize the recent progress in the synthesis of transition metal boride/phosphide based catalysts and their application in catalyzing hydrolysis of boron hydrides. We highlight a number of strategies to enhance the catalytic efficiency and stability of metal boride/phosphide catalysts, such as component optimizing, structure tailoring and substrate engineering. Remarkably, the supported Co–W–B catalyst enables a high H₂ release rate of 15 000 mL min⁻¹ g⁻¹ and an activation energy lower than 30 kJ mol⁻¹ towards the hydrolysis of NaBH₄. Furthermore, the main concerns and issues like identifying a real catalytic activity center and revealing the catalytic mechanisms are also discussed, along with perspectives on future research in this field.