Effect of preparation route on Sr2TiO4 catalyst for the oxidative coupling of methane.

Abstract Four different preparation routes were used to synthesize Sr 2 TiO 4 with the structure of layered perovskite: sol-precipitation (SP), co-precipitation (CO), citrate precursor (CT) and mechanochemical (MA) methods with further calcinations at 1100 °C. The XDR, XPS, BET, SEM techniques showed that the different preparation routes caused the formation of layered perovskite phase with different admixture phases, particle sizes and the surface enrichment with layered perovskite (for SP and MA samples) or strontium oxide (for CO and CT samples). The trend of increasing of CH 4 conversion and C 2 -yield in oxidative coupling of methane at 800-900 °C was found to be the following: SP≈MA > CO > CT samples. The C 2 -yield of the most active catalysts was measured to be about 12%. Graphical abstract Unlabelled Image Highlights • Sr2TiO4 with the structure of layered perovskite was prepared by different routes. • The presence of strontium compounds on the catalysts surface provides low CH4 conversion. • Mechanochemical activation is the most attractive method to synthesize Sr2TiO4. • The C2-yield of the most active catalysts was measured to be 12% at 850oC. [ABSTRACT FROM AUTHOR]