The effect of high energic charge carriers generated from plasmonic metals on driving chemical reactions has been received a lot of attention recently. A previous experiment has shown that, by integrating the aluminum with copper(I) oxide, this hybrid plasmonic catalyst was able to accelerate the reverse water gas shift reaction at 175 oC. In this study, we apply DFT calculations at the ground state and excited states to explore the mechanism of CO2 photo-dissociation (the likely rate-determining step in CO2 conversion) on an Al@Cu2O core-shell structure in terms of the possible reaction pathway and the possible charge transfer mechanism. We find that the interfacial interaction between CO2 and Cu2O creates new low-lying antibonding states, population of which enables the dissociation of CO2 in the range of visible light. Compared to the ground state, the value of the intrinsic activation energy does not change much at excited states; however, the effective barrier could reduce by 2 eV if the system decays to ground potential energy surface right before crossing the transition state. We also show that it is less challenging for the hot electrons originally excited from aluminum to populate the antibonding states of CO2 than the excited electrons generated from Cu2O directly via dipole-dipole coupling. Nevertheless, the charge transfer is more preferrable for later states than the initial state along the reaction coordinates due to the stronger hybridization of the dissociated species with Cu2O. Our findings shed lights on the feasibility of visible light to be able to facilitate the CO2 dissociation reaction at low temperature, showing a promising effect of the plasmonic catalysis in mitigating the carbon emission.

Plasmon-induced CO2 conversion on Al@Cu2O: A DFT study

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.