Understanding Catalyst Activity
In-situ temperature-programmed XRD measurements of a selected Cu/Zn/Al-catalyst precursor
Cu/Zn/Al-oxide catalysts are commonly used in industrial low-pressure methanol synthesis. The reaction, starting from synthesis gas (mixture of CO2, CO, and H2) is catalyzed by a combination of CuO, ZnO, and Al2O3 oxides whereas the final catalyst is obtained by a reduction of CuO to metallic Cu under H2 flow (1,2,3). It is widely accepted that the active species for the methanol synthesis are metallic Cu-clusters. ZnO is supposed to be essential for a homogeneous distribution of the active Cu-species at elevated temperatures. The catalysts are produced by a precipitation process, first forming mixed Cu/Zn/Al hydroxy carbonates. These hydroxy carbonates are calcined in a second step, forming the mixed oxides of Cu, Zn and Al. The role of the hydroxy carbonate phases and their decomposition during the thermal treatment are supposed to have a strong influence on the catalytic behaviour of the final catalysts obtained.
1. R.T. Figueiredo, A. Martinez-Arias, M. Lopez Granados, J.L.G. Fierro, J. Catal. 178 (1998) 146-152
2. G.C. Chinchen, K. Mansfield, M. S. Spencer, Chemtech (1990) 693
3. R.G. Herman in "New Trends in CO activation" Stud. Surf. Sci. Catal., Chap. 7. Elsevier, Amsterdam, 1991
Get the document
To receive this document please enter your email below.