International Journal of Hydrogen Energy, Vol.45, No.36, 18398-18410, 2020
Ethanol CO2 reforming on La2O3 and CeO2-promoted Cu/Al2O3 catalysts for enhanced hydrogen production
3%Ce- and 3%La-promoted 10%Cu/Al2O3 catalysts were synthesized via a sequential incipient wetness impregnation approach and implemented for ethanol CO2 reforming (ECR) at 948-1023 K and stoichiometric feed ratio. CeO2 and La2O3 promoters reduced CuO crystallite size from 32.4 to 27.4 nm due to diluting impact and enhanced the degree of reduction of CuO -> Cu-0. Irrespective of reaction temperature, 3%La-10%CuAl2O3 exhibited the highest reactant conversions, H-2 and CO yields followed by 3%Ce-10% Cu/Al2O3 and 10%Cu/Al2O3. The greatest C2H5 OH and CO2 conversions of 87.6% and 55.1%, respectively were observed on 3%La-10%Cu/Al2O3 at 1023 K whereas for all catalysts, H-2/CO ratios varying from 1.46 to 1.91 were preferred as feedstocks for Fischer-Tropsch synthesis. Activation energy for C2H5OH consumption was also reduced with promoter addition from 53.29 to 47.05 kJ mol(-1). The thorough CuO -> Cu-0 reduction by H-2 activation was evident and the Cu-0 active phase was resistant to re-oxidation during ECR for all samples. Promoters addition reduced considerably the total carbon deposition from 40.04% to 27.55% and greatly suppressed non-active graphite formation from 26.94% to 4.20% because of their basic character and cycling redox enhancement. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.