MATERIALS DERIVED FROM SYNTHETIC ORGANO-CLAY COMPLEXES AS NOVEL HYDRODESULFURIZATION CATALYST SUPPORTS

A series of mesoporous synthetic organo-clay complexes has been prepar ed by hydrothermal crystallization of gels containing silica, magnesiu m hydroxide, lithium fluoride, and an organic of choice, followed by c alcination to remove the organics. The organic serves to impart struct ural order to the inorganic network that does not disappear upon its r emoval. The choice of organic modifier can be used to control the pore structure of the resulting mesoporous materials. Pore size distributi ons 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 resul ts show performance commensurate with commercial catalysts for the mes oporous materials when a model heavy oil feed is used (1 wt% S as dibe nzothiophene in hexadecane), Temperature programmed reduction experime nts of used catalysts suggest a relationship between HDS activity and ease of reduction of the CoMo/clay catalysts. Reactivity of the CoMo/c lay also correlates with the percentage of mesopore volume remaining a fter reaction. Losses in mesopore volume are largely recouped by recal cination, suggesting that reversible coke is formed inside the pore st ructure of clays faster than inside conventional alumina. (C) 1998 Els evier Science B.V.