Unlocking Photocatalytic CO 2 Conversion to Ethylene Glycol by Microdroplet‐Enabled Interfacial Electric Field

ABSTRACT The electrochemical carbon dioxide (CO 2 ) reduction features attractive potentials of carbon neutrality and chemical upgrading, while the types of products from photocatalysis or electrocatalysis still remain limited. The conversion of CO 2 into ethylene glycol, an important chemical that is typically produced by thermo‐catalytic process, has not been achieved by photocatalysis or electrocatalysis. Herein, we demonstrate a microdroplet‐enhanced photocatalytic strategy with a Pd‐TiO 2 catalyst, which allows for efficient conversion of CO 2 into ethylene glycol with high selectivity. The electro‐sprayed microdroplets provide a high interfacial electric field that facilitates deep reduction of CO 2 into *CH 3 , as well as generation of reactive *OH intermediates to form CH 3 OH. The in situ formed CH 3 OH is further photo‐catalytically activated to cleave a C−H bond to *CH 2 OH, followed by the C−C coupling to produce ethylene glycol. Under 1‐sun illumination, the electro‐sprayed microdroplets and Pd‐TiO 2 catalyst exhibited a high CO 2 ‐to‐ethylene glycol conversion rate of 2985 µmol L −1 h −1 , which significantly outperformed those by only photocatalysis or only electro‐sprayed microdroplets, revealing the capability of combining multiple energy fields for tuning reaction pathways and advancing green synthesis.