Reactivity of perovskites on oxidative coupling of methane

Well-defined structures like ABO3 (A = Ba, Sr, Ca; and B = Ti, Zr) perovskites were prepared by a sol-gel method which permits the formation of a crystalline structure at low-calcination temperatures (about 700 C). These perovskites are of interest as catalysts in the oxidative coupling of methane (OCM). The perovskite structures were characterised by XRD, SEM and BET surface area methods, and the carbonate present at the surface was determined by FTIR spectroscopy. Reactivity studies showed that the perovskite structures are stable under OCM conditions. The yield increases followed the sequence Ca less than Sr less than Ba and Zr less than Ti, and a stable BaTiO3 gives a C2 yield of 15% at 800 C. 30 refs.