Preparation and characterization of ASnO3 (A=Ca, Sr or Ba) tin compounds for methane oxidative coupling

Tin containing perovskites ASnO3 (A=Ca, Sr, Ba) are prepared by a solgelmethod starting from tin oxygenated precursor (SnO) or from chlorinated precursors (SnCl4). The respective reactivity tests in oxidative coupling show that perovskites prepared from chlorinated precursors have a much higher C2 hydrocarbons selectivity than that obtained from oxygenated ones (70% compared to 40% for BaSnO3). This difference in reactivity is interpreted by the modification of the basicity of the system by bulk or surface chlorine (CO2 thermodesorption).