Phosphate-assisted synthesis of ultrathin and thermally stable alumina nanosheets as robust Pd support for catalytic combustion of propane

Two-dimensional γ-Al 2 O 3 nanosheet with rich pentacoordinate Al 3+ sites which can nicely stabilize noble metals via strong interactions between metal and support has been focused. However, the synthesis of ultrathin and highly thermal-stable Al 2 O 3 is challenging. Herein, we report an effective approach to synthesize ultrathin Al 2 O 3 nanosheets with regular leaf-like architecture as well as high thermal-stability. A novel intercalation-swelling-exfoliation pathway was proposed to elucidate the formation of ultrathin sheet-like structure and then its morphology/thickness could be further adjusted via a dissolution-growth induced by phosphate. Meanwhile, the presence of phosphate further enhanced thermal stability of Al 2 O 3 nanosheets due to the occupation or depletion of high-reactive sites and surface hydroxy groups. Subsequently, the thermally stable γ-Al 2 O 3 nanosheets with moderate anchoring sites was used as a support of Pd and investigated for catalytic combustion of propane. The Pd/Al 2 O 3 nanosheet exhibited a superior catalytic activity for propane combustion and the complete conversion was below 300 °C, more importantly, the outstanding resistance to high temperature (1000 °C) was observed, which was ascribed to the re-dispersion of Pd particles and the occurrence of strong metal-support interaction (SMSI) at high temperature.