Photocatalytic reduction of CO2 into organic molecules can promote the CO2 utilization and retard the greenhouse effect which has attracted considerable attention. Due to the high surface-bulk ratio, two-dimensional materials are promising candidates as catalysts. In this work, we performed first-principles computations to investigate the reduction of CO2 at the oxygen vacancy in the MXene monolayers. Among three kinds of MXene, Ti2CO2, V2CO2 and Ti3C2O2, Ti2CO2 exhibits the best catalytic performance for the reduction of CO2. The reaction path CO2 → HCOO → HCOOH was identified as the preferable one with a low energy barrier of 0.53 eV. The much higher energy barriers of the reaction pathways for other single-carbon organic products guarantee the high selectivity for HCOOH. Moreover, CO and H2 can introduce sufficient oxygen vacancies on O-terminated MXene, indicating the experimental feasibility of the catalysts. This work provides a new insight for the design of the catalysts for the reduction of CO2 and further widens the applications of MXene-based materials.

Ti2CO2 (O-terminated MXene) with O vacancies as a highly active and selective catalyst for reduction of CO2 into HCOOH

254th National Meeting (2017)

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