Cr2O3 promoted skeletal Cu catalysts for the reactions of methanol steam reforming and water gas shift

Promotional effects of chromia on the structure and activity of skeletal copper catalysts for methanol steam reforming and water gas shift have been studied. Catalysts were prepared by leaching CuAl2 alloy particles in aqueous NaOH solutions containing sodium chromate at various concentrations. XPS spectra showed that the surface of the resulting catalysts mainly consisted of Cr3+ compounds and Cu-0. Cu+ and/or Cu2+ were not observed by XPS. Increasing the concentration of chromate in the leach liquor resulted in decreases in pore diameter and copper crystallite size but significant enhancement of BET surface area was observed while the total pore volume was maintained. The addition of small amounts of chromate to the leach liquor significantly enhanced the Cu surface area. However, higher concentrations of chromate in the leach liquor decreased the Cu surface areas although the total surface areas increased. The activities of Cr2O3 promoted skeletal copper catalysts for both methanol steam reforming and water gas shift reactions were determined separately. The results indicated that deposition of Cr2O3 On Skeletal copper catalysts significantly improved the specific activities for these reactions. Chromia is found to act as a structural and catalytic promoter for these reactions. (C) 2000 Elsevier Science B.V. All rights reserved.