Oxidative Coupling of Methane over Lithium-Promoted Zinc Oxide Catalyst

Abstract

Alkali doped ZnO samples were examined as catalysts for the conversion of methane to ethylene and ethane. Among the catalysts tested, 12.5 mol% Li-promoted zinc oxide was the most active and selective for the formation of C2-hydrocarbons. The highest yield of C2-compounds was 24.8% and the fraction of ethylene in C2-compounds was over 80% .

The Role of [M+O−] Centers (M+– Group IA Ion) in the Activation of Methane on Metal Oxides

“…The most stable oxide of potassium is K0 2 , and the 02-ion may be capable of abstracting hydrogen from CH 4 at ca. 700°C.…”

“…The oxidative dimerization of methane to ethane and its sequential conversion to ethylene have been studied over a variety of metal oxide catalysts which are modified by the addition of alkali metal ions [1][2][3][4][5][6][7]. Maximum C 2 (ethane plus ethylene) yields of 15-20% have been achieved as summarized in Table I.…”

The Catalytic Activity of Zinc Oxides from Single Source Precursors with Additives for the C–H Acitivation of Lower Alkanes

“…In the first publication on this topic, Matsuura et al investigated the activity of alkali doped zinc oxides for the OCM reaction and found that ZnO doped with Li is the most active catalyst [8]. Zhang et al reported that the mechanism of the OCM reaction on Li doped zinc oxide is similar to the one proposed for Li doped MgO [9].…”

Oxidative Coupling of Methane Using Inorganic Membrane Reactors

“…The temperature range in which the gas phase reactions become predominant shifts to lower temperatures-at elevated pressures. Thus the use of a large fraction of inert gas as diluent generally leads to higher selectivity [69]. A higher CH4/02 ratio increases the C2 selectivity but naturally decreases the percent conversion.…”