Ultrasonically controlled deposition-precipitation - Co-MoHDS catalysts deposited on wide-pore MCM material

Mo and Co oxides were precipitated under ultrasonication treatment from Mo( CO)(6) and Co(CO)(3)NO dissolved in decalin. Introduction of wide-pore Al-M CM-41 material with an average pore diameter 8.3 nm and a surface area of 8 40 m(2)/g increased the Mo oxide precipitation rate by an order of magnitud e. This is a result of an ultrasonically induced chemical interaction betwe en metal carbonyl (oxide) and the surface silica atomic layer yielding surf ace silicates (XPS, MAS NMR). It was demonstrated for the first time that u ltrasonication of such a slurry yields deposition-precipitation of the corr esponding metal oxide, forming a close-packed monolayer at the support's su rface (Nz adsorption, HR-TEM, XPS, XRD). Ultrasonically controlled depositi on-precipitation produced similar to 45 wt% MoO3 loading, which is saturati on of the wide-pore Al-MCM-41 surface monolayer. The high-loading Go-MolAl- MCM-41 catalyst prepared by ultrasonically controlled deposition-precipitat ion was 1.7 times more active in HDS of dibenzothiophene, based on the reac tion rate normalized per catalyst weight, than commercial Go-Mo-Al catalyst . (C) 2001 Academic Press.