Materials derived from synthetic organo-clay complexes as novel hydrodesulfurization catalyst supports

A series of mesoporous synthetic organo-clay complexes has been prepared by hydrothermal crystallization of gels containing silica, magnesium hydroxide, lithium fluoride, and an organic of choice, followed by calcination to remove the organics. The organic serves to impart structural order to the inorganic network that does not disappear upon its removal. The choice of organic modifier can be used to control the pore structure of the resulting mesoporous materials. Pore size distributions appear in some cases to be related to the type of polymer packing upon clay formation in situ. These materials are being explored as Go-Mo hydrodesulfurization (HDS) catalyst supports. Preliminary HDS results show performance commensurate with commercial catalysts for the mesoporous materials when a model heavy oil feed is used (1 wt% S as dibenzothiophene in hexadecane), Temperature programmed reduction experiments of used catalysts suggest a relationship between HDS activity and ease of reduction of the CoMo/clay catalysts. Reactivity of the CoMo/clay also correlates with the percentage of mesopore volume remaining after reaction. Losses in mesopore volume are largely recouped by recalcination, suggesting that reversible coke is formed inside the pore structure of clays faster than inside conventional alumina. (C) 1998 Elsevier Science B.V.