Electronic impact of Ni2P nanoparticle size on hydrogenation rates

Abstract

Abstract Nickel phosphide, Ni2P, nanoparticles supported on SiO2 show a marked volcano shaped size dependence on hydrogenation of phenol. Kinetic analysis and physicochemical characterization shows the electron density of Ni to increase with increasing Ni2P size, enhancing in turn the H2 adsorption strength. For particles below 15\xa0nm, H adsorbs weakly causing a low surface coverage of H, gradually increasing with particle size. For large particles, hydrogen binds too strongly causing a high coverage but low catalytic activity. The remarkable size dependence of the electronic properties show that Ni2P particle size can be used to fine-tune its activity for hydrogenation.