Catalytic activity of model aluminium-doped TiO2 catalysts I. A study of promoter effects on the decomposition of N2O
1986; Elsevier BV; Volume: 100; Issue: 1 Linguagem: Inglês
10.1016/0021-9517(86)90071-0
ISSN1090-2694
Autores Tópico(s)TiO2 Photocatalysis and Solar Cells
ResumoThe influence of Al3+ dopents on the catalytic activity of TiO2 for the decomposition of N2O has been studied using the solid solution technique. Substitutional solid solutions were prepared up to about 4 at.% Al; between 4 and 10 at.% a two- or three-phase system developed containing the solid solution and a separate corundum phase. The catalysts were well characterised by X-ray diffraction, ESR, conductivity measurements and Static SIMS. Al3+ is shown to generate Ti3+ during a complex charge compensation in the TiO2 lattice. Catalytic activity for N2O decomposition was little affected by Al doping in Ti(1 − x) AlxO2 up to x = 0.003. Between x = 0.003 and x = 0.03 there was a 10-fold increase in activity. Between x = 0.03 and x = 0.1 activity fell by a factor 10. The data have been interpreted in terms of the developing electronic interactions between the Ti3+ ions generated as a consequence of Al3+ doping. It is shown that earlier theories developed to explain the activity of transition metal ions in insulating and semiconducting oxides are applicable to this type of system.
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