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Title: In situ infrared study of methanol synthesis from CO{sub 2}/H{sub 2} on titania and zirconia promoted Cu/SiO{sub 2}

In situ infrared study of methanol synthesis from CO{sub 2}/H{sub 2} on titania and zirconia promoted Cu/SiO{sub 2} In situ infrared studies of methanol synthesis from H{sub 2}/CO{sub 2} have been conducted over Cu/SiO{sub 2} promoted with ZrO{sub 2}, TiO{sub 2}, and a mixture of TiO{sub 2}/ZrO{sub 2}, with the aim of establishing the means by which the added oxide influences the activity of the catalyst for methanol synthesis. While ZrO{sub 2} and TiO{sub 2} individually enhance the methanol synthesis activity of Cu/SiO{sub 2}, a significantly greater enhancement is achieved by addition of both oxides simultaneously. In the absence of oxide addition, infrared spectra taken under reaction conditions suggest that methanol synthesis from CO{sub 2} takes place on the surface of Cu exclusively. When ZrO{sub 2} is added to the catalyst, there is strong evidence for methanol synthesis on the surface of both Cu and ZrO{sub 2}. Catalysis on the surface of ZrO{sub 2} occurs as a consequence of CO{sub 2} adsorption to form b-HCO{sub 3}-Zr, which then undergoes progressive hydrogenation to form methanol. The required atomic hydrogen is supplied from the surface of Cu particles by spillover. When TiO{sub 2} is added there is no evidence for catalysis occurring on the oxide surface, but strong evidence for an enhancement in the level of reaction occurring on the more » surface of Cu. The observed increase in the rate of methanol synthesis is attributed to a reconstruction of the Cu particles to expose the (100) surface, which have been demonstrated to be significantly more active than the (110) or (111) surfaces. The infrared spectra observed when a mixture of ZrO{sub 2} and TiO{sub 2} is added to Cu/SiO{sub 2} resembles a composite of the spectra observed upon addition of the individual oxides, and hence, the enhanced rate of methanol synthesis is ascribed to the combined effects of ZrO{sub 2} and TiO{sub 2}. « less
Authors: ; ; ;
Publication Date:
OSTI Identifier:OSTI ID: 354385
DOE Contract Number:AC03-76SF00098
Resource Type:Journal Article
Resource Relation:Journal Name: Journal of Catalysis; Journal Volume: 184; Journal Issue: 1; Other Information: PBD: 15 May 1999
Sponsoring Org:USDOE, Washington, DC (United States)
Country of Publication:United States
Language:English
Subject: 10 SYNTHETIC FUELS; CARBON DIOXIDE; METHANATION; HYDROGENATION; METHANOL; SYNTHESIS; COPPER; SILICON OXIDES; TITANIUM OXIDES; ZIRCONIUM OXIDES; CATALYTIC EFFECTS; PROMOTERS