Polymer-templated mesoporous hybrid oxides of Al and Cu: highly porous sorbents for ammonia

Abstract

Hybrid mesostructures consisting of copper and aluminum oxides were synthesized via co-condensation of suitable precursors in the presence of a triblock copolymer, Pluronic F127. These mesostructures were prepared using aluminum isopropoxide and copper nitrate as precursors. The aforementioned polymer-templated synthesis afforded copper oxide–alumina hybrid materials with well-developed mesoporosity and a high specific surface area (130–460 m² g⁻¹). Controlled heating of these materials in nitrogen resulted in template free copper oxide–alumina mesostructures showing high affinity toward NH₃ and moderate affinity toward CO₂ at elevated temperatures (∼50 °C). The temperature programmed desorption studies revealed a superior NH₃ sorption capacity of the samples with a high Cu content at 50 °C (over 16 mmol g⁻¹). The high affinity of mesoporous copper oxide–alumina materials toward NH₃, their good thermal stability together with their high surface area make these materials attractive sorbents for various applications, where large and accessible pores with high loading of catalytically active metal oxides are needed.