Influence of the Tortuosity and the Acidity of H-ZSM-5 on the Selectivities in Ethylation of Toluene

The primary product of title reaction is p-ethyltoluene, which isomerizes to m- and very slowly to o-ethyltoluene. The yields of ethyltoluenes are decreased by hydrodeethylation. Disproportionate accompanies the above transformations. The change of yields and selectivities of p-ethyltoluene with the spacetime, the reaction temperature (350-500 * C), catalyst pretreatment temperature (400-700 * C), time on flow and with the amount of adsorbed pyridine or 2,6-lutidine are discussed on the basis of kinetical considerations. Inclusions of oxides of phosphorus and/or magnesium suppress the side reactions by decreasing the concentration of the Bronsted acid sites.