Characterization of some perovskite oxides based on YBa2Co3O7-x in relation to their use in methanol production

The oxidized and weakly reducible perovskite oxide YBa2Cu3O7-x, (YBCO) has been prepared as a catalyst, supported on gamma -Al2O3. It was further modi fied by (i) impregnation with Ru and Pd and (ii) cobalt incorporation via c o-precipitation. All the catalysts were either 20% (w/w) YBCO/gamma Al2O3 o r 2% (w/w) Ru, Pd or Co/20% (w/w) YBCO/gamma -Al2O3. The catalysts were cha racterized using temperature programmed reduction (TFR), surface area measu rements and X-ray diffraction (XRD) studies before and after various treatm ents. They were studied as catalysts in the pressure range 20-50 atmosphere s and in the temperature range 523-573 K in an autoclave equipped with a sp inning basket catalyst container. The Pd-, Ru- and Go-modified catalysts ga ve predominantly methanation products, along with some C-2-C-4 hydrocarbons . However the YBCO/gamma -Al2O3 catalyst exhibited significant methanol sel ectivity at 50 atmospheres and at 523 K X-ray diffraction studies revealed the presence of Cu(0), Cu(I) and Cu(II) after reduction and the species Cu( 0) and Cu(I) are probably essential to CH3OH production. (C) 2000 Society o f Chemical Industry.