Non-oxidative Coupling of Methane to Ethylene Using Mo2 C/[B]ZSM-5.

Methane non-oxidative coupling to ethylene was investigated on Mo2 C/[B]ZSM-5 catalyst at 923 K and atmospheric pressure. In contrast to Mo2 C/[Al]ZSM-5 catalysts for methane aromatization, this material exhibits very high ethylene selectivity (>90 %) and low aromatics (benzene and naphthalene) selectivity. The much weaker Brønsted acidity of [B]ZSM-5 leads to a slow rate of ethylene oligomerization. The stability of the catalyst is greatly enhanced with 93 % of the initial reaction rate remaining after 18 h of time on stream. In-situ UV/VIS spectra indicate that prior to carburization, mono/binuclear Mo oxides are initially well dispersed onto the zeolite support. Mo carbides clusters, formed during carburization with methane, appear similar to clusters formed in [Al]ZSM-5, as indicated by the X-ray Absorption Spectroscopy (XAS) data.