Regulation of d‑Band Electrons to Enhance the Activity of Co-Based Non-Noble Bimetal Catalysts for Hydrolysis of Ammonia Borane

The catalytic activity of the catalyst closely depends on its electronic structure, but the relationship between electronic structure and the catalytic activity in the ammonia borane (NH₃BH₃, AB) catalyzed hydrolysis reaction is still unclear. Here, we prepared Co-based non-noble metal (Fe, Ni, Cu, and Zn) alloy nanoparticles (NPs) and determined the electronic structure by a valence band spectrum (VBS) obtained from X-ray photoelectron spectrometer (XPS) measurement and theoretical calculations. The relationship of the d-band center (ε_d) and activity exhibits volcano-shape behaviors. The activity of CoCu alloys is superior to other metals, which is due to the electronic structure affecting the adsorption and desorption behavior of water in the hydrolysis reaction. The acid etching method formed SCoCu with different Cu content, and the coexistence of surface defects made the ε_d further regulated. These results provide new insights into the relationship between the electronic structure of the catalyst and its catalytic AB hydrolysis activity.