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

Two-dimensional gamma-Al2O3 nanosheet with rich pentacoordinate Al3+ 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 Al2O3 is challenging. Herein, we report an effective approach to synthesize ultrathin Al2O3 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 Al2O3 nanosheets due to the occupation or depletion of high-reactive sites and surface hydroxy groups. Subsequently, the thermally stable gamma-Al2O3 nanosheets with moderate anchoring sites was used as a support of Pd and investigated for catalytic combustion of propane. The Pd/Al2O3 nanosheet exhibited a superior catalytic activity for propane combustion and the complete conversion was below 300 degrees C, more importantly, the outstanding resistance to high temperature (1000 degrees 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.

Automated summary

The successful synthesis of ultrathin Al2O3 nanosheets with regular leaf-like architecture and high thermal stability was achieved in this study. The morphology/thickness could be adjusted and thermal stability enhanced by phosphate, while the nanosheets were used as a support for Pd in catalytic combustion of propane, exhibiting superior activity and resistance to high temperatures.