A-site cation exfoliation of amorphous SmMnxOy oxides for low temperature propane oxidation

•A novel multi-component amorphous SmMnxOy catalyst was designed for low-temperature propane combustion;•Hierarchical porous structure was developed through A-site exfoliation of amorphous SmMnxOy base;•The reaction mechanism and rate determining step of propane oxidation over multi-component amorphous SmMnxOy were revealed;•The SMO-A-HNO3 catalyst with highest lattice oxygen activity and mobility displayed the best catalytic performance;