Surface enhanced Raman scattering from a ternary catalyst Cu/ZnO/Al2O3 under reaction conditions

Surface enhanced Raman scattering (SERS) from molecules chemisorbed on a ternary catalyst Cu/ZnO/Al2O3 has been observed under reaction conditions for co-adsorption of H2CO2 (= 41) at high temperature (T = 240°C) an high pressure (p = 20 bar). The vibrational modes of the formate ion the key intermediate in methanol synthesis together with different species of adsorbed carbonate, carbon dioxide and water have been identified. A complicated structure of the spectra in the energy region of 1000–1800 cm−1 proves the simultaneous chemisorption of different intermediates with similar structures. The spectral characteristics of a catalyst with long ageing time indicates the formation of carbon on the surface of the catalyst.