NANOSIZED MIXED METAL-OXIDE CATALYSTS AND THEIR PREPARATION

摘要

A mixed metal-oxide catalyst uniformly controlled to obtain narrow particle size distribution as particles with uniform shape and nanosize, a method for preparing the same, a method for preparing a precursor of the mixed metal-oxide catalyst, and a method for efficiently preparing fatty acid ester ethoxylate with narrow alkyleneoxide added mole number distribution using the mixed metal-oxide catalyst are provided. A method for preparing a precursor of a mixed metal-oxide catalyst comprising a template material and mixed metal hydroxides comprises the steps of: (a) dissolving a template material into distilled water; (b) injecting soluble salts and carbonates of M(II) and M(III) into a solution of the step(a) to dissolve the soluble salts and carbonates into the solution and mix the soluble salts and carbonates with the solution; and (c) adding a base into the mixed solution for forming a coprecipitate of the template material and mixed metal hydroxides represented by a formula, [M(II)xM(III)y(OH)2x+3y-2z(A^2-)z nH2O], wherein M(II) represents bivalent metals including Mg, Zn, Ca and Cu, M(III) represents trivalent metals including Al, Cr, Fe and B, A^2- represents organic or inorganic interlayer anions including CO3^2-, n has a value ranging from 0.2 to 4 as the number of water of crystallization, x/y has a value ranging from 1 to 8, and z/(x+y) has a value ranging from 0.167 to 0.05. A method for preparing a mixed metal-oxide catalyst comprises the step of firing the prepared precursor of the mixed metal-oxide catalyst at a temperature from 400 to 700 deg.C.