A DRIFTS STUDY OF THE MORPHOLOGY AND SURFACE ADSORBATE COMPOSITION OF AN OPERATING METHANOL SYNTHESIS CATALYST

The nature of the species adsorbed on a Cu/ZnO/Al2O3 catalyst while it was producing methanol has been elucidated in this study using DRIFTS. The species are carbonates, formate, CO, oxygen atoms (similar to 2% of a monolayer) and methoxy on the Cu and methoxy on the ZnO. The frequencies observed for the C-O stretch on Cu, 2076, 2092, 2105 and 2132 cm(-1), have revealed the morphology of the copper component of the operating catalyst. The surface of the copper is predominantly the (111) face (similar to 65%) (the 2076 cm(-1) peak) with the (755) (the 2092 cm(-1) peak) and the (311) (the 2105 cm(-1) peak) faces occupying roughly 20% and 15%, respectively, of the copper area. The 2132 cm(-1) peak derives from CO adsorbed on Cu+ site on the copper which is similar to 2% of a monolayer.