Ultrafine Cu-Pd bimetallic clusters enhance asymmetric electron distribution to boost C-C coupling in photothermal CO2-to-ethanol conversion

Converting CO 2 to ethanol through photothermal catalysis faces significant challenges due to it involves multi-electron reduction and kinetically sluggish C-C coupling process. Here, copper and a minor quantity of palladium are encapsulated within the cage of UiO-66 using a dual-solvent-sonication method to form ultrafine Cu 2 O/Cu-Pd clusters. The Cu-Cu 2 O serves as an electron center to enhance CO 2 uptake and activation, while the incorporation of Pd accelerates H 2 activation. Due to differences in electronegativity , electrons tend to transfer from Cu to Pd, which reduces the electrostatic repulsion between intermediates and facilitates the coupling of *CO and *CHO. The photothermal ethanol yield of Cu 6 Pd@UiO-66 reached 1077.69 μmol·g cat –1 ·mL –1 with a selectivity of 94.62%, representing an 11.64-fold increase over the non-illumination, and a 3.11-fold enhancement compared with Cu 6 @UiO-66. This study offers evidence supporting the promotion of C-C coupling through an asymmetric electron distribution , potentially advancing the conversion of CO 2 to liquid products. This research presents the synthesis of ultrafine Cu-Pd bimetallic clusters via a dual-solvent-sonication approach, which enhances asymmetric electron distribution and significantly boosts C-C coupling in the photothermally driven CO 2 -to-ethanol conversion. • Ultrafine Cu 2 O/Cu-Pd clusters were constructed by a dual-solvent-sonication method. • The photothermal ethanol yield of Cu 6 Pd@UiO-66 reached 1077.69 μmol·g cat –1 ·mL –1 . • The yield improved 11.64-fold over non-illumination and 3.11-fold over Cu 6 @UiO-66. • Cu 6 Pd@UiO-66 illustrated the stronger photogenerated carrier capability. • The asymmetric distribution of electrons promotes the coupling of *CO and *CHO.