Adsorption and activation of ethene by zeolite-H-ZSM-5

Abstract

Thermogravimetric adsorption data for C₂H₄ and H₂O and i.r. and n.m.r. spectroscopic results are combined to obtain information on the role played by acidic Brönsted sites in the H-ZSM-5 zeolite in the adsorption and activation of C₂H₄. Water and ethene compete for such sites in various ways which depend on the pretreatment of the zeolite. Physisorbed water prevents the adsorption of C₂H₄. Ethene is readily activated and reacts on the Brönsted acidic sites, even at room temperature. There is further evidence for the formation of carbenium-type intermediates.