A Study of the Mn, Co and Ni Environment in the As-synthesized and Rehydrated-calcined Aluminophosphate with Chabazite-like Topology

Abstract

Diffuse-reflectance spectroscopy (DRS), X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) methods are applied to an investigation of Mn, Co and Ni local environments in MnAlPO, CoAlPO, and NiAlPO materials with chabazite-like topology. For all three products, insertion of the transition metals into tetrahedral Al-sites has been found. Calcination and rehydration of the as-synthesised materials cause a change of the oxidation number and co-ordination geometry of Mn and Co, while the oxidation and co-ordination number of Ni remain unaffected.