Sr, Mg-substituted titanates on the basis of La2TiO5: effect of substitution on catalytic activity in the oxidative methane coupling

Based on La2TiO5 layered perovskite, the complex oxide materials Sr2aLa2-2aTiO5-5 and Mg2aLa2-2aTiO5-5 (a = 0-1) were synthesized by sol-precipitation method. The X-ray diffraction analysis, the specific surface area, and scanning electron microscopy techniques showed that Sr-substituted samples contain phases of the 'layered' perovskite (SrLa)2TiO5-5 as well as La2O3, La(OH)3 and TiO2. The Mg-substituted samples contain the phases of the 'double' perovskites (Mg,La)TiO3-5, and La(OH)3. The specific surface area of as prepared samples varied within 0.5-4.2 m2/g. The catalytic properties of the materials were investigated by the reaction the oxidative coupling of methane to ethane in a fixed-bed microcatalytic reactor at temperatures from 600 to 950 degrees C. Most active in the OCM reaction were the samples in which the substitution degree of lanthanum a was equal to 0.1-0.3. Sr-substituted samples showed higher activity than Mg-substituted ones. The best activity was revealed for Sr2aLa2-2aTiO5-5 (a = 0.1). (c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

Based on La2TiO5 layered perovskite, complex oxide materials were synthesized by the sol-precipitation method. The Sr-substituted samples showed higher catalytic activity compared to the Mg-substituted ones.