Excessive CO2 emission is a dangerous greenhouse gas that negatively impacts society and our ecosystem. Strategies to reduce CO2, such as CO2 reduction, therefore play an important role in a sustainable future. One of the most significant challenges to reducing CO2 is its extremely stable linear form. Experimentally, Cu/TiO2 has shown promise for CO2 photocatalytic reduction. Cu/TiO2 promotes activation of CO2 to a bent structure, which is considered the first step in the CO2 reduction process. We have shown both experimentally and computationally how small atoms or clusters of Cu on TiO2 may activate CO2. These atomic catalysts have a number of advantages over traditional large catalyst particles, as they have higher surface/volume ratios and active sites typically having lower coordination number. Surface defects may play an important role in CO2 reduction. Our work focuses on modeling TiO2 surfaces with oxygen vacancies, and determining how such vacancies may affect the CO2 reduction process when small Cu clusters are present. All calculations were performed using density functional theory (DFT). Our results show that oxygen vacancies near Cu atoms may lead to enhanced CO2 activation. We have also investigated how the presence of a photo-excited electron affects CO2 activation. Our results show that tailoring TiO2 surfaces with defects in conjunction with atomic catalysts may lead to effective catalysts reducing CO2.

Effect of defects in metal cluster/metal oxide photocatalysts for CO2 photoreduction

255th National Meeting (2018)

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