Exchange of CO 2 with CO as Reactant Switches Selectivity in Photoreduction on Co-ZrO 2 from C 1-3 Paraffin to Small Olefins

• Published in: Angewandte Chemie International Edition 2024-12, Vol.63 (51), p.e202412090
• Main Authors: Loumissi, Tarik, Ishii, Rento, Hara, Keisuke, Oyumi, Tomoki, Abe, Ikki, Li, Chongxu, Zhang, Hongwei, Hirayama, Rumiko, Niki, Kaori, Itoi, Takaomi, Izumi, Yasuo
• Format: Article
• Language: English
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202412090

Photocatalytic reduction of CO into C hydrocarbons completes a C-neutral cycle. The reaction pathways of photocatalytic generation of C paraffin and C H from CO are mostly unclear. Herein, a Co -ZrO photocatalyst converted CO into C paraffin, while selectively converting CO into C H and C H (6.0±0.6 μmol h  g , 70 mol %) only under UV/Visible light. The photocatalytic cycle was conducted under CO and H , with subsequent evacuation and flushing with CO. This iterative process led to an increase in the population of C H and C H up to 61-87 mol %, attributed to the accumulation of CH species at the interface between Co nanoparticles and the ZrO surface. CO adsorbed onto the O vacancies of the ZrO surface, with resulting COH species undergoing hydrogenation on the Co surface to yield C paraffin using either H or H O (g, l) as the reductant. In contrast, CO adsorbed on the Co surface, converted to HCOH species, and then split into CH and OH species at the Co and O vacancy sites on ZrO , respectively. This comprehensive study elucidates intricate photocatalytic pathways governing the transformation of CO into paraffin and CO to olefins.