High surface area crystalline metal aluminates and a method of manufacture thereof at lower temperature

Abstract

Sintering is an important issue in creating crystalline metal oxides with high porosity and surface area, especially in the case of high-temperature materials such as metal aluminates. Herein we report a rationally designed synthesis of metal aluminates that diminishes the surface area loss due to sintering. Metal aluminate (e.g. MeAlOor MeAlO−Me=Mg, Mn, Fe, Ni, Co, Cu, La, or Ce; or mixture thereof) supported on γ-AlOwith ultralarge mesopores (up to 30 nm) was synthesized through microwave-assisted peptization of boehmite nanoparticles and their self-assembly in the presence of a triblock copolymer (Pluronic P123) and metal nitrates, followed by co-condensation and thermal treatment. The resulting materials showed the surface area up to about 410 m·g, porosity up to about 2.5 cm·g, and very good thermal stability. The observed enhancement in their thermomechanical resistance is associated with the faster formation of the metal aluminate phases. The nanometer scale path diffusion and highly defective interface of γ-alumina facilitate the counter diffusion of Meand Alspecies and further formation of the metal aluminate phase.