Materials aspects of titanium-doped aluminas: 14%Ti/-Al2O3/Cu and sulfided Al2O3-TiO2/NiMo
2002 (English)In: Materials Chemistry and Physics, Vol. 73, no 2, 242-51 p.Article in journal (Refereed) Published
Materials aspects of titanium-doped alumina catalysts are discussed in light of a partly new synthesis route, ion exchange reactions and sulfidation. Starting with a solution of the isopropoxides of aluminum and titanium, we aimed at an Al:Ti ratio of 6:1, which corresponds to the maximum acidity of the final product. Transmission electron micrographs showed that the synthesis gave a product of nearly monodisperse, rectangular particles and X-ray diffractograms revealed an amorphous to nano-crystalline structure reminiscent of -Al2O3. The Brunauer-Emmet-Teller area was 340m2g-1 and the H+ titration found 3acidic sitesnm-2. These numbers indicate that the titanium modification may fourfold increase the ion exchange capacity of a regular alumina. The importance of titanium modification for catalysis is discussed in connection with selective catalytic reduction with hydrocarbon reactions over Cu/14%Ti-Al2O3 and hydrogenation of 1-Me-naphthalene over sulfided NiMo/Al2O3-TiO2. The Ti4+ ions in the alumina lattice are almost irreducible, but infrared spectra suggested that these ions act as dispersion agents not only for adsorbed Cu2+ ions, but also for a supported phase of sulfided NiMo. Finally, we show that a simple weight control can be used to monitor the sulfidation and to indicate if the synthesis has produced a separate, reducible titania phase.
Place, publisher, year, edition, pages
2002. Vol. 73, no 2, 242-51 p.
Titanium-doped alumina, Catalyst dispersion, Denox reactions, Hydrotreatment reactions
IdentifiersURN: urn:nbn:se:umu:diva-9008DOI: doi:10.1016/S0254-0584(01)00392-3OAI: oai:DiVA.org:umu-9008DiVA: diva2:148679