Phytic acid-derivative Co2B-CoPOx coralloidal structure with delicate boron vacancy for enhanced hydrogen generation from sodium borohydride

Abstract

Application of transition metal boride (TMB) catalysts towards hydrolysis of NaBH4 holds great significance to help relieve the energy crisis. Herein, we present a facile and versatile metal-organic framework (MOF) assisted strategy to prepare Co2B-CoPOx with massive boron vacancies by introducing phytic acid (PA) cross-linked Co complexes that are acquired from reaction of PA and ZIF-67 into cobalt boride. The PA etching effectively breaks down the structure of ZIF-67 to create more vacancies, favoring the maximal exposure of active sites and elevation of catalytic activity. Experimental results demonstrate a drastic electronic interaction between Co and the dopant phosphorous (P), thereby the robustly electronegative P induces electron redistribution around the metal species, which facilitates the dissociation of B-H bond and the adsorption of H2O molecules. The vacancy-rich Co2B-CoPOx catalyst exhibits scalable performance, characterized by a high hydrogen generation rate (HGR) of 7716.7 mL min−1 g−1 and a low activation energy (Ea) of 44.9 kJ/mol, rivaling state-of-the-art catalysts. This work provides valuable insights for the development of advanced catalysts through P doping and boron vacancy engineering and the design of efficient and sustainable energy conversion systems.