Preparation of mesoporous nanocrystalline tetragonal zirconia for catalytic methane combustion

Abstract

Mesoporous nanocrystalline tetragonal zirconia (ZrO2) materials were synthesised via combining the soft templating method with the solid–liquid method. In brief, mesostructured zirconium hybrids were first prepared via the soft templating method and then ground with solid copper nitrate salts followed by low temperature heat treatment and further high temperature calcination in air. Finally, mesoporous nanocrystalline tetragonal ZrO2 materials were obtained after etching in acid solution. The characterisation results indicate that the obtained mesoporous ZrO2 materials have higher specific surface areas in the range of 100–300 m2 g−1 and pore diameters centred at 4·0–5·0 nm. The pore walls are composed of tetragonal ZrO2 nanocrystalline particles with an average size of 1–15 nm. These mesoporous nanocrystalline tetragonal ZrO2 materials as catalysts demonstrate good catalytic activity toward methane combustion, characterised by lower conversion temperatures (650–700°C) and active energies (75–90 kJ mol−1) than those of the reported ZrO2 materials, meaning their potential applications as catalysts or catalyst supporters in methane combustion.