From the Surface Structure to Catalytic Properties of Al5Co2(21̅0): A Study Combining Experimental and Theoretical Approaches

Replacing noble metal catalysts with inexpensive, environmentally harmless, active, selective, and stable substitutes is a great challenge for the chemical industry. In this paper, the noble metal-free Al5Co2(21̅0) complex intermetallic surface is experimentally identified as active and selective for the semihydrogenation of butadiene. The catalyst surface structure and chemical composition are determined by experimental techniques—surface X-ray diffraction (SXRD) and scanning tunneling microscopy—combined with ab initio calculations. Theoretical investigations of the adsorption properties under reaction conditions demonstrate that the surface Co atomic density drastically impacts the thermodynamic feasibility of the hydrogenation reaction, and they provide information on the reaction mechanism. This work offers insights into the rational design of Al-based catalysts for hydrocarbon hydrogenation reactions.