Effects of A-site non-stoichiometry in YxInO3+δ on the catalytic performance during methane combustion

Abstract

A novel non-stoichiometric Y_xInO_3+δ (YIO-x, 0.8 ≤ x ≤ 1.04) perovskite catalyst with a large number of oxygen vacancies and high specific surface area was synthesized using glycine self-propagating gel combustion. It was found that low levels of non-stoichiometry in the A site of Y_xInO_3+δ effectively increased the amount of oxygen desorption by 39–42% when compared to the original (YIO-1) due to Y-deficiency and oxygen vacancies. Further investigations showed that the non-stoichiometry also brings a significant change to the Lewis acid sites on the surface of the sample, which confirmed to be a great promoter for the catalytic combustion of methane. In addition, the catalytic performance increased with the increasing intensity of acid sites. After 50 h of the stability test, the catalysts maintained high activity, indicating their good catalytic stability.