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.

Graphical abstractLaMnO3/Al2O3 catalysts have been prepared by a novel method with polyvinyl pyrrolidone (PVP) as the complexing agent. The obtained catalysts performed excellent thermal stability, which should be due to the strong interaction between Al2O3 and LaMnO3.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► LaMnO3/Al2O3 catalysts have been prepared with PVP as a complexing agent. ► The catalysts exhibited excellent activity and thermal stability. ► Gently changes in surface area and catalytic activity were observed from 600 to 1000 °C. ► The strong thermal-resistance was ascribed to the interaction between LaMnO3 and Al2O3.