Precision loading of Pd on Cu species for highly selective CO2 photoreduction to methanol

Abstract

Photocatalytic reduction of CO2 to yield methanol is a promising strategy for CO2 conversion and utilization. This work combines the designs of both efficient charge transfer pathway and precision loading to construct a novel Pd-Cu/TiO2 photocatalyst with high selectivity toward methanol. Accordingly, the optimal methanol (CH3OH) production rate and selectivity of 2 % Pd-Cu/TiO2 at relatively mild conditions (0.5 MPa, 50 °C) by using ion exchange method can reach to 71.84 μmol g−1h−1 and 91.71 %, respectively. Precisely loading Pd on Cu species instead of TiO2 facilitates the concentration of electrons on Cu species. Moreover, loading Pd via ion exchange method constructs more oxygen vacancies (OVs), thus improving the visible light absorption and charge separation of catalysts. Additionally, in situ FT-IR testing results unveils the evolution from CO2 to CH3OH, including the critical intermediates of HCOO* and H3CO*. This work deeply studies the precision loading of Pd and provides a novel design of phothcatalysts.