Cooperative role of cobalt and gallium under the ethanol steam reforming on Co/CeGaOx

The performance of gallium promoted cobalt-ceria catalysts for ethanol steam reforming (ESR) was studied using H2O/C2H5OH = 6/1 mol/mol at 500 degrees C. The catalysts were synthetized via cerium-gallium co-precipitation and wetness impregnation of cobalt. A detailed characterization by N-2-physisorption, XRD, H-2-TPR and TEM allowed the normalization of contact time and rationalization of the role of each catalysts component for ESR. The gallium promoted catalyst, Co/Ce90Ga10Ox, was more efficient for the ethanol conversion to H-2 and CO2, and the production of oxygenated by-products (such as, acetaldehyde and acetone) than Co/CeO2. The catalytic performance is explained assuming that: (i) bare ceria is able to dehydrogenate ethanol to ethylene; (ii) Ce-O-Ga interface catalyzes ethanol reforming; (iii) both Ce-O-Co and Ce-O-Ga interfaces takes part in acetone production; and (iv) cobalt sites further allow C-C scission. It is suggested that a cooperative role between Co and Ce-O-Ga sites enhance the H-2 and CO2 yields under ESR conditions. (c) 2022 Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC.

Automated summary

The performance of gallium promoted cobalt-ceria catalysts for ethanol steam reforming was studied. Gallium promoted catalyst showed higher conversion efficiency of ethanol and production of oxygenated by-products compared to cobalt-ceria catalyst. The role and mechanism of gallium promotion were analyzed and explained through detailed characterization and analysis of the catalyst.