The Oxidation of Ethane to Ethylene over Strontium Containing Methane Coupling Catalysts

The oxidative dehydrogenation of ethane to ethylene over three types of strontium-containing catalysts has been investigated. The catalysts are much more active and selective than for the corresponding methane coupling reaction and ethylene yields of up to 40% are possible with a 20%ethane/10%oxygen feed. Lanthana and magnesia based catalysts are the most active but strontium carbonate/aluminosilicate catalysts are more selective. Although DRIFTS measurements of the latter show the presence of strontium silicates and aluminates in the bulk XPS indicates that the surface layers are largely SrCO₃ and that the high selectivity is related to the presence of some sodium. Carbonates also dominate at the surface of the other catalysts but the magnesia-based ones show oxides as well in conformity with DRIFTS measurements of the bulk.