Ultrasonically Controlled Deposition–Precipitation: Co–Mo HDS Catalysts Deposited on Wide-Pore MCM Material

Mo and Co oxides were precipitated under ultrasonication treatment from Mo(CO)6 and Co(CO)3NO dissolved in decalin. Introduction of wide-pore Al-MCM-41 material with an average pore diameter 8.3 nm and a surface area of 840 m2/g increased the Mo oxide precipitation rate by an order of magnitude. This is a result of an ultrasonically induced chemical interaction between metal carbonyl (oxide) and the surface silica atomic layer yielding surface silicates (XPS, MAS NMR). It was demonstrated for the first time that ultrasonication of such a slurry yields deposition–precipitation of the corresponding metal oxide, forming a close-packed monolayer at the supportʹs surface (N2 adsorption, HR-TEM, XPS, XRD). Ultrasonically controlled deposition–precipitation produced ∼45 wt% MoO3 loading, which is saturation of the wide-pore Al-MCM-41 surface monolayer. The high-loading Co–Mo/Al-MCM-41 catalyst prepared by ultrasonically controlled deposition–precipitation was 1.7 times more active in HDS of dibenzothiophene, based on the reaction rate normalized per catalyst weight, than commercial Co–Mo–Al catalyst.