Synthesis of alumina supported LaMnO3 with excellent thermal stability by a PVP-assisted route

LaMnO3/Al2O3 catalysts were successfully prepared by a novel method with polyvinyl pyrrolidone (PVP) as complexant and characterized by XRD, TGA, IR, BET, XPS and TEM techniques. The TGA and IR characterizations of the precursor revealed that LaMnO3 structure was formed under mild conditions without combustion of any organic compounds. The obtained catalysts exhibited better activity for methane combustion than those prepared by citrate method, mainly due to larger pore volume, more active oxygen species on surface and the formation of a pure perovskite structure. The high surface area of about 122 m2 g−1 was retained even after calcined at 1000 °C; and interestingly, no phase transformation or solid-state reaction was observed. This fact indicated the excellent thermal stability of catalysts, which was ascribed to the strong interaction between the support and active phase.