CuO-Co3O4 Composite Nanoplatelets for Hydrolyzing Ammonia Borane

The development of cheap and high-performance catalysts for the hydrolysis of ammonia borane (AB) for hydrogen production is a hotspot in the field of nanocatalysis and hydrogen energy. In this paper, we report the simple synthesis of CuO-Co3O4 composite nanoplatelets that were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The effects of the molar ratios of CuO to Co3O4 in the composites and the calcination temperatures on the catalytic activity of the obtained products in AB hydrolysis were investigated. In addition, the active species of the catalysts and the synergy of the CuO-Co3O4 nanoplatelets in AB were explored. It was determined that the turnover frequency of the CuO-Co3O4 nanoplatelets can reach 33.4 min(-1). By incorporating CuO into Co3O4, the reducibility of the resultant CuO-Co3O4 nanoplatelets was remarkably improved, leading to enhanced catalytic performance. The active species is the CoCu alloy formed on the surface of CuO-Co3O4 by the coreduction of CuO and Co3O4 with AB. These findings can help to better understand the catalytic behavior of oxide composite-based catalysts and the design of other inexpensive, high-performance catalysts.