Exploring the catalytic potential of AuxPt4-x clusters on TiC and ZrC (001) surfaces for hydrogen dissociation

Abstract

The adsorption and dissociation of hydrogen on bimetallic clusters of AuxPt4-x supported on TiC (0 0 1) and ZrC (0 0 1) surfaces, has been studied using periodic boundary density functional theory (DFT). Simulations reveal that H2 exhibits moderate adsorption energies on AuxPt4-x/TMC (TM = Ti and Zr) systems and dissociates with a tiny barrier comparable to archetypal catalyst such as Pt (0 0 1). The incorporation of two different metal atoms (Au and Pt) in the cluster results in a noticeable enhancement of catalytic activity compared to clusters of equivalent size composed of pure metals like Pd, Cu, and Pt when deposited on TiC (0 0 1). Furthermore, our calculations reveal that the adsorbed H atom on the AuPt3 cluster is prone to spill over the C sites on both surfaces, and the migration of hydrogen atoms on both supports is thermodynamically favorable. In essence, our results provide compelling evidence that when AuxPt4-x clusters are supported on surfaces with a significant degree of polarity, as TMCs, the complete system H2/AuxPt4-x/TMC can efficiently activate and dissociate H2 concurrently, highlighting the potential for enhanced catalytic efficiency in hydrogenation reactions. © 2024