Effect of preparation method on Ni2P/SiO2 catalytic activity for NaBH4 methanolysis and phenol hydrodeoxygenation

A comparative study has been performed on Ni2P/SiO2 catalysts prepared by: (i) conventional temperature-programmed reduction (TPR) of calcined precursors following wet impregnation of the support, (ii) TPR of a sol gel prepared NiO/SiO2 precursor impregnated with NH4H2PO4 and (iii) a solution-phase reaction in the presence of the SiO2 support using Ni(acac)(2) and trioctylphosphine. Catalyst characterization shows that the Ni2P prepared by the solution-phase method has a uniform particle size (7.5 +/- 0.8 nm) and H species can easily transfer from the nickel sites to the SiO2 support on this catalyst. These properties result in a high NaBH4 methanolysis to hydrogen activity. In contrast, the sol gel prepared Ni2P/SiO2 has a relatively high catalytic activity for phenol hydrodeoxygenation due to a higher concentration of Ni delta+ species that act as Lewis acid sites and metal sites, and a higher Ni2P crystallinity. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.