Use of a catalyst comprising a mixed oxide in a basic heterogeneous catalyzed chemical reaction e.g. triglyceride transesterification to prepare biodiesel, where the catalyst is obtained by calcining a bilayer metal hydroxide

Use of a catalyst (I) comprising a mixed oxide in a basic heterogeneous catalyzed chemical reaction is claimed, where (I) is obtained by calcining a bilayer metal hydroxide (II). Use of a catalyst (I) comprising a mixed oxide in a basic heterogeneous catalyzed chemical reaction is claimed, where (I) is obtained by calcining a bilayer metal hydroxide of formula ([(M 1>+>) y(M 2>+>) 1-y-x(M 3>+>) x(OH) 2](x-y) +>(A) (x-y)/n(n ->).mH 2O) (II). M 2>+>at least a divalent inorganic cation comprising Mg 2>+>, Ca 2>+>, Sr 2>+>, Ba 2>+>, Zn 2>+>, Cd 2>+>, Cu 2>+>, Ni 2>+>, CO 2>+>, Fe 2>+>, Pb 2>+>or Sn 2>+>; M 1>+>at least one monovalent inorganic cation comprising alkali metals +>, Cu +>or Ag +>; M 3>+>at least one trivalent rare earth metal cation or a mixture of at least one trivalent rare earth metal cation and at least one another trivalent inorganic cation comprising Al 3>+>, B 3>+>, Ga 3>+>, Cr 3>+>, Mo 3>+>, In 3>+>or Fe 3>+>; A : an inorganic or organic anion; either x : 0.05-0.95; and y : 0-0.95; or x+y : = 1; n : 1-4; and m : 0.1-2. Independent claims are included for: (1) the preparation of (II) comprising coprecipitation of M 3>+>-metal salts, M 2>+>-metal salts and/or M 1>+>metal salts from a aqueous solution using a precipitating agent, which is potassium carbonate or a mixture of potassium carbonate and potassium hydroxide; (2) the bilayer metal hydroxide (II) with a Brunauer-Emmett-Teller surface of 110-300 m 2>/g; and (3) the mixed oxide catalyst (I). Die vorliegende Erfindung betrifft die Verwendung von seltenerdmetallhaltigen Mischoxidkatalysatoren zur basisch heterogen katalysierten Herstellung einer chemischen Verbindung, insbesondere zur heterogen basenkatalysierten Herstellung von Fettsäurealkylestern durch Umesterung von Triglyceriden und zur Herstellung von α, -ungesättigten Carbonylverbindungen durch Aldolkondensation von Carbonylverbindungen. Ferner betrifft die vorliegende Erfindung seltenerdmetallhaltige Mischoxidkatalysatoren mit hoher BET-Oberfläche sowie ein Verfahren zur Herstellung solcher Mischoxidkatalysatoren.