Ys. Bhat et al., ACTIVITY STABILIZATION OF GA-MFI ZEOLITE CATALYST MODIFIED BY CHEMICAL-VAPOR-DEPOSITION, Bulletin of the Chemical Society of Japan, 69(2), 1996, pp. 469-472
The chemical vapor deposition of silica on Ga-MFI zeolite was carried
out using tetraethyl orthosilicate. The enhancement in para selectivit
y during toluene alkylation with the extent of silica deposition was c
losely monitored. The effect of reaction temperature on the behavior o
f silica deposited Ga-MFI zeolite was established. A deactivation tren
d in toluene conversion was observed when the zeolite was employed for
alkylation for longer periods. The reasons for catalytic deactivation
and stability enhancement by in situ coking are discussed.