Co0.45W0.55 Nanocomposite from ZIF-67: An Efficient and Heterogeneous Catalyst for H2 Generation Upon NaBH4 Hydrolysis

Abstract It is still a significant challenge to replace noble metal based catalysts by non-noble metal-based, highly efficient and earth-abundant catalysts in the H 2 generation upon hydrolysis of sodium borohydride. Herein, we first design and synthesize the highly selective and heterogeneous Co x W y nanocomposites from ZIF-67 as robust catalysts for H 2 production upon the hydrolysis of sodium borohydride. Among them, the Co 0.45 W 0.55 nanocatalyst exhibits the highest TOF of 1770 mL H2 g cat −1 min −1 (the TOF related to only cobalt nanoparticles 8401 mL H2 g Co −1 min −1 ) over pure ZIF-67 or W nanoparticles and other ones. In addition, the Co 0.45 W 0.55 catalyst has been successfully recycled at least 5 times without any significant activity loss, although the W (VI) has been partly reduced to W (V), W (IV) and W (0) in the hydrolysis of sodium borohydride. This stability is taken into account by the highly active Co species rather than the activity of W itself. Based on the results obtained, we have shown that Co 0.45 W 0.55 nanocomposite can be a potential candidate for the replacement of a noble metal catalyst for H 2 generation. Graphic Abstract