The effects of zirconia morphology on methanol synthesis from COand H2 over Cu/ZrO2 catalysts: Part I -- Steady-State Studies
The effect of zirconia phase on the activity and selectivityof Cu/ZrO2 for the hydrogenation of CO has been investigated. Relativelypure t-ZrO2 and m-ZrO2 were prepared with high surface areas (~; 145m2/g). Copper was then deposited onto the surface of these materials byeither incipient-wetness impregnation or deposition-precipitation. For afixed Cu surface area, Cu/m-ZrO2 was tenfold more active for methanolsynthesis than Cu/t-ZrO2 from a feed of 3/1 H2/CO at 3.0 MPa andtemperatures between 473 and 523 K. Cu/m-ZrO2 also exhibited a higherselectivity to methanol. Increasing the Cu surface area on m-ZrO2resulted in further improvement in activity with minimal change inselectivity. Methanol productivity increased linearly for both Cu/t-ZrO2and Cu/m-ZrO2 with increasing Cu surface area. The difference in inherentactivity of each phase paralleled the stronger and larger CO adsorptioncapacity of the Cu/m-ZrO2 as quantified by CO-TPD. The higher COadsorption capacity of Cu/m-ZrO2 is attributed to the presence of a highconcentration of anionic vacancies on the surface of m-ZrO2. Suchvacancies expose cus-Zr4+ cations, which act as Lewis acid centers andenhance the Bronsted acidity of adjacent Zr-OH groups. The presence ofcus-Zr4+ sites and adjacent Bronsted acidic Zr-OH groups contributes tothe adsorption of CO as HCOO-Zr groups, which are the initial precursorsto methanol.
- Research Organization:
- Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
- Sponsoring Organization:
- USDOE Director. Office of Science. Office of AdvancedScientific Computing Research. Office of Basic Energy Sciences. ChemicalSciences Geosciences and Biosciences Division
- DOE Contract Number:
- AC02-05CH11231
- OSTI ID:
- 900645
- Report Number(s):
- LBNL--57001-Pt.-1; BnR: KC0302010
- Journal Information:
- Journal of Catalysis, Journal Name: Journal of Catalysis Journal Issue: 1 Vol. 233; ISSN 0021-9517; ISSN JCTLA5
- Country of Publication:
- United States
- Language:
- English
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