Synergy between Palladium Single Atoms and Nanoparticles via Hydrogen Spillover for Enhancing CO2 Photoreduction to CH4. Issue 16 (12th March 2022) - Liu, Peigen
Abstract: Selective photoreduction of carbon dioxide (CO2 ) into carbon‐neutral fuels such as methane (CH4 ) is extremely desirable but remains a challenge since sluggish multiple proton–electron coupling transfer and various C1 intermediates are involved. Herein, a synergistic function between single Pd atoms (Pd1 ) and Pd nanoparticles (PdNPs ) on graphitic carbon nitride (C3 N4 ) for photocatalytic CO2 methanation is presented. The catalyst achieves a high selectivity of 97.8% for CH4 production with a yield of 20.3 µmol gcat. −1 h −1 in pure water. Mechanistic studies revealed that Pd1 sites activated CO2, while PdNPs sites boosted water (H2 O) dissociation for increased H* coverage. The H* produced by PdNPs migrate to the Pd1 sites to promote multiple proton–electron coupling transfer via hydrogen spillover. Moreover, the adjacent Pd1 and PdNPs effectively stabilized intermediates such as *CHO, thereby favoring the pathway for CH4 production. This work provides a new perspective into the development of selective photocatalytic CO2 conversion through the artful design of synergistic catalytic sites. Abstract : Synergistic Pd1 and PdNPs form a functional catalyst for enhancing photocatalytic CO2 methanation. Pd1 activate CO2, while PdNPs boost H2 O dissociation. The H* produced by PdNPs migrates to Pd1 via hydrogen spillover to promote multiple proton–electron coupling transfer processes. Moreover, the adjacent Pd1 and PdNPs stabilize intermediates, such as *CHO. Therefore, efficient photocatalytic CO2 to CH4 is highly favored.