Ethylene Dimerization in Nickel Containing MCM-41 and AlMCM-41 Studied by Electron Spin resonance and Gas Chromatography

摘要

Dehydrated nickel-containing mesoporous MCM-41 and AlMCM-41 materials are catalytically active for ethylene dimerization. The catalytic activity is shown to be due to nickel(I) species in ion-exchange positions. The ethylene dimerization activity and product distribution is different in Ni-MCM41 and Ni-AlMCM-41. Electron spin resonance studies show that in isolated nickel(I) species can be stabilized, which converts to a Ni(I)-C_2D_4 complex after ethylene adsorption. After subsequent heating to 343 K two new species are observed, which can be ascribed to Ni(I)-product complexes.