Boosted Catalytic Activity toward the Hydrolysis of Ammonia Borane by Mixing Co- and Cu-Based Catalysts

Abstract

Promoting the activity of heterogeneous catalysts in the hydrolysis of ammonia borane for hydrogen production is still a challenging topic for researchers in the hydrogen energy and catalysis fields. Herein, we present a universal, simple and efficient strategy to boost the catalytic performance toward AB hydrolysis by mixing Co- and Cu-based catalysts for the first time. Synergistic catalysts with remarkably enhanced activity can be obtained by mixing a Co-based catalyst and a Cu-based catalyst together, such as Co3O4 and Cu3(MoO4)2(OH)2, Co3O4 and Cu3(PO4)2, Co3(PO4)2 and Cu3(MoO4)2(OH)2, Co3(PO4)2 and Cu3(PO4)2, and CuO and Co3O4. For example, the turnover frequency (TOF) for the mixture catalyst of Co3O4 and Cu3(MoO4)2(OH)2 with a mass ratio of 4:1 is up to 77.3 min−1, which is approximately 11.5 times higher than that of the sum of Co3O4 and Cu3(MoO4)2(OH)2. The reasons for these findings are discussed in detail. The observations and conclusions in this work may provide a guideline for promoting the hydrolysis of ammonia borane through a simple and effective approach.