The size-dependent catalytic activity of Ni 2 P for hydrodesulfurization (HDS) remains unstudied because the traditional temperature programmed reduction (TPR) method used in catalyst preparation results in highly polydisperse Ni 2 P particles. The ability to control the Ni 2 P particle size in the range 5−20 nm by varying the quantity of oleylamine in solution-phase arrested precipitation reactions is reported. Particles were introduced to a high surface area silica support (Cab-O-Sil, M-7D grade, 200 m 2 /g) via incipient wetness, and HDS activity was probed against dibenzothiophene (DBT). All samples were less active than TPR prepared materials, and the smallest particles were the least active, contrary to expectation. This is attributed in part to particle sintering under HDS conditions. Sintering occurs independently of wt% loading of catalyst, time, incipient wetness procedure, and ionic additives, at all temperatures greater than 200 °C. Sintering is minimized by encapsulation of Ni 2 P nanoparticles in a mesoporous silica shell, achieved by sol−gel silica formation around Ni 2 P-containing surfactant liquid crystal assemblies and subsequent calcination, resulting in a doubling of HDS activity.

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Ru2P/SiO2 and RuP/SiO2 catalysts were prepared by the temperature-programmed reduction (TPR) of uncalcined precursors containing hypophosphite ion (H2PO2 –) as the phosphorus source. The Ru2P/SiO2 and RuP/SiO2 catalysts had small average particle sizes (∼4 nm) and high CO chemisorption capacities (90–110 μmol/g). The Ru phosphide catalysts exhibited similar or higher furan (C4H4O) hydrodeoxygenation (HDO) activities than did a Ru/SiO2 catalyst, and the phosphide catalysts favored C4 hydrocarbon products while the Ru metal catalyst produced primarily C3 hydrocarbons.

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