Ethylation of Benzene with Ethane over MFI Zeolite-Supported Pb Catalyst

Conversion of a short alkane such as ethane into chemical feedstocks instead of alkene becomes important for efficient use of natural gas and refinery off-gas. Here direct ethylation of benzene with ethane into ethylbenzene was attempted. Preceding studies clarified catalytic activity of Pt-loaded MFI-type zeolite. In addition, for a similar reaction, i.e., methylation of benzene with methane, we previously found catalytic activity of Co/MFI. Based on these backgrounds, various metal elements supported by zeolites were investigated as catalysts for a reaction between ethane and benzene. Pt, Pb, Zn, Mo, Co, and Ga/MFI showed high activity for ethylation of benzene with ethane. Among them, Pb/MFI showed high reaction rate for formation of desired products (ethylbenzene, styrene and diethylbenzene), while the others brought side reactions, i.e., formation of C₃₋₅ aliphatic hydrocarbons, toluene, naphthalene, and its derivatives. Pb/MFI showed stable activity, while Pt, Zn, and Mo/MFI showed deactivation due to carbonaceous formed by the side reactions.