Theoretical Insight into the Reaction Mechanism of Ethanol Steam Reforming on Co(0001)

Abstract

By using plane-wave density functional theory, the reaction mechanism of ethanol steam reforming (ESR) on the Co(0001) surface is investigated by systematically exploring the barriers and reaction energies of elementary steps. Our results suggest that ESR is initiated by decomposition of ethanol: CH3CH2OH* → CH3CH2O* → CH3CHO* → CH3CO* → CH3* + CO*. This is followed by the water–gas shift (CO* + OH* → COOH* → CO2* + H*) or direct oxidation (CO* + O* → CO2*) reaction to produce CO2. The reaction between CO* and OH*/O* is considered to be the key step in ESR. The proposed mechanism is consistent with most available experimental data and provides theoretical insight into the reaction pathways of the ESR process on cobalt catalysts.