The interaction of H2O2 with TiAlPO-5 molecular sieves: probing the catalytic potential of framework substituted Ti ions

A combination of EPR, ENDOR and HYSCORE experiments has been used to investigate the reactivity of hydrogen peroxide with TiAlPO-5 materials under both hydrated and anhydrous conditions. Superoxide radical anions, generated upon reaction, are used as paramagnetic probes to investigate the nature and reactivity of framework incorporated Ti ions. Super hyperfine interactions with 27Al, 31P and 1H are resolved, which allow a detailed mapping of the local environment of the adsorbed O2− ions. Evidence is provided for the first time of a specific redox activity associated with Ti ions incorporated at framework Al sites of TiAlPO materials.