Palladium phosphide nanoparticles as highly selective catalysts for the selective hydrogenation of acetylene

Abstract Pd 3 P and PdP 2 phases of ca . 4 nm particle diameter were prepared on a TiO 2 support by an impregnation route. Data from the hydrogenation of acetylene under both non-competitive and competitive conditions showed that PdP 2 /TiO 2 exhibits enhanced selectivity and stability relative to Pd 3 P. Furthermore, the selectivity produced over PdP 2 (84% ethylene selectivity @ 100% acetylene conversion) compares favorably with recently reported materials. XPS and CO-IR measurements reveal that the incorporation of P helps to break up contiguous Pd sites. This in turn is thought to affect the adsorption and desorption of reactants/products and thus improves selectivity. This work reveals that the incorporation of P into Pd materials could be regarded as a promising approach to develop new and improved Pd-based catalyst by creating a means to control the nature of the active sites.