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

The 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 [Cu 2 (CN) 6 ] and [Zn(en) 3 ] 6 [Cu 2 (CN) 7 ] 2 [Cu(CN) 3 ] · 8.4H 2 O 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/CO 2 /H 2 . 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)