Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.


Issue 15, 2017
Previous Article Next Article

Catalytic consequences of Ga promotion on Cu for CO2 hydrogenation to methanol

Author affiliations

Abstract

The promotion of Ga on SiO2 supported Cu in the hydrogenation of CO2 to methanol at 800 kPa and 200–280 °C was investigated. Cu/SiO2 and CuGa/SiO2 catalysts were prepared by a water-in-oil microemulsion technique resulting in Cu clusters of 4–6.5 nm. It was found that Ga addition increased the methanol formation rate by an order of magnitude without significantly changing that for reverse water gas shift (RWGS). This trend is also evidenced by the decrease in the apparent activation barrier for methanol formation from 78 (for Cu/SiO2) to 26–39 kJ mol−1 when Ga was added, but not for RWGS (107–132 kJ mol−1). Kinetic and in situ DRIFTS analyses revealed that formate intermediates are adsorbed on both Cu and Ga2O3 and that methoxy hydrogenation could be the rate determining step of methanol synthesis. In the case of RWGS, a zero order of CO formation with respect to H2 concentration was consistent with a redox mechanism and with the reaction occurring predominantly on Cu sites. The results suggest that Ga promotes Cu increasing methanol selectivity, likely by creating new active sites for methanol formation without modifying its oxidation state, which under reaction conditions remains mostly metallic.

Graphical abstract: Catalytic consequences of Ga promotion on Cu for CO2 hydrogenation to methanol

Back to tab navigation

Supplementary files

Article information


Submitted
20 May 2017
Accepted
04 Jul 2017
First published
05 Jul 2017

Catal. Sci. Technol., 2017,7, 3375-3387
Article type
Paper

Catalytic consequences of Ga promotion on Cu for CO2 hydrogenation to methanol

J. C. Medina, M. Figueroa, R. Manrique, J. Rodríguez Pereira, P. D. Srinivasan, J. J. Bravo-Suárez, V. G. Baldovino Medrano, R. Jiménez and A. Karelovic, Catal. Sci. Technol., 2017, 7, 3375
DOI: 10.1039/C7CY01021D

Social activity

Search articles by author

Spotlight

Advertisements