Coprecipitation: An excellent tool for the synthesis of supported metal catalysts - From the understanding of the well known recipes to new materials

Constant-pH co-precipitation is a standard synthesis technique for catalyst precursors. The general steps of this synthesis route are described in this work using the successfully applied industrial synthesis of the Cu/ZnO/(Al2O3) catalyst for methanol synthesis as an example. Therein, co-precipitation leads to welldefined and crystalline precursor compound with a mixed cationic lattice that contains all metal species of the final catalyst. The anions are thermally decomposed to give the mixed oxides and the noblest component, in this current case copper, finally segregates on a nano-metric level to yield supported and uniform metal nanoparticles. Recent examples of the application of this synthesis concept for supported catalysts are reported with an emphasis on the layered double hydroxide precursor (Cu,Zn,A1; Ni,Mg,A1; Pd,Mg,A1; Pd,Mg,Ga). This precursor material is very versatile and can lead to highly loaded base metal as well as to mono- and bi-metallic highly dispersed noble metal catalysts. (C) 2014 Elsevier B.V. All rights reserved.