Catalytic Activity of Copper Oxide/Zinc Oxide Composites Prepared by Thermolysis of Crystallographically Defined Bimetallic Coordination Compounds

Abstract

AbstractThe suitability of bimetallic coordination compounds in the systems Cu/Zn/CN and Cu/Zn/CN/ethylenediamine as precursors for CuO/ZnO was explored. The kinetic and thermodynamic equilibria in these systems are discussed. The introduction of ethylenediamine led to crystalline precursorcompounds, and the bimetallic coordination compounds[Zn(en)]2[Cu2(CN)6] and [Zn(en)3]6[Cu2(CN)7]2[Cu(CN)3]·8.4H2O were structurally characterised. The oxide mixtures of CuO/ZnO, prepared by mild thermolysis of the precursor compounds, were tested for their catalytic activity in the formation of methanol from synthesis gas, i.e. CO/CO2/H2. While the oxide mixtures from Zn[Cu(CN)3] were not catalytically active, the oxide mixtures derived from the crystalline compounds with ethylenediamine as the ligand had about 20–30 % of the activity of an industrial methanol catalyst. This underscores the importance of the origin of the catalyst, i.e. the dependence of its activity from the structure of its precursor. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)