CHARACTERISATION OF A NEW GOLD CATALYST SUPPORTED ON MIXED OXIDES FOR PURE HYDROGEN PRODUCTION AND PURIFICATION

A characterisation study of a new gold catalyst, supported on ceria-titania and prepared by a deposition-precipitation method, is presented. In order to discuss the catalytic data of water gas shift reaction (WGSR) activity and to get an interpretation of the positive effect of CeO₂, TEM, UV-Vis and FTIR analysis have been undertaken. HRTEM has shown presence of very highly dispersed gold clusters with average size of 2 nm and presence of highly defective support phases. FTIR data of CO chemisorption have evidenced positive gold ions stabilized by the mixed oxide surface. The study of CO, O₂ and H₂ interaction by FTIR shows that the addition of ceria has a positive effect on the preferential oxidation of CO in the presence of an excess of hydrogen (PROX). UV-Vis spectra have shown a band-gap position at lower frequency than those of rutile and of anatase, suggesting a potential use of this catalyst as photoactive material, under visible light.