| 摘要 |
1488281 Alumina-rare earth oxide composite RHONE-POULENC INDUSTRIES 9 Jan 1975 [10 Jan 1974 18 Nov 1974] 960/75 Heading B1E [Also in Division Cl] An alumina-based substance containing 1 to 15% wt. (based on alumina) of at least one of the oxides of La, Nd, Pr or Th, together with agglomerated active alumina is formed by agglomerating alumina, autoclaving the agglomerated alumina, and (a) before agglomeration, (b) after agglomeration and before autoclaving or (c) after autoclaving, adding the metal oxide or a precursor thereof to the alumina, and drying and calcining the agglomerated autoclaved impregnated product at a temperature not exceeding 1200‹C. The active alumina may be obtained by partial dehydration of hydrargillite or alumina gel in a current of hot gas. The substance is of use as a catalyst support, e.g. ,in I.C. engine exhaust gas treatment. |
