Clustering‐Resistant Cu Single Atoms on Porous Au Nanoparticles Supported by TiO2 for Sustainable Photoconversion of CO2 into CH4

Abstract Photocatalysts based on single atoms (SAs) modification can lead to unprecedented reactivity with recent advances. However, the deactivation of SAs‐modified photocatalysts remains a critical challenge in the field of photocatalytic CO 2 reduction. In this study, we unveil the detrimental effect of CO intermediates on Cu single atoms (Cu‐SAs) during photocatalytic CO 2 reduction, leading to clustering and deactivation on TiO 2 . To address this, we developed a novel Cu‐SAs anchored on Au porous nanoparticles (CuAu‐SAPNPs‐TiO 2 ) via a vectored etching approach. This system not only enhances CH 4 production with a rate of 748.8 μmol ⋅ g −1 ⋅ h −1 and 93.1 % selectivity but also mitigates Cu‐SAs clustering, maintaining stability over 7 days. This sustained high performance, despite the exceptionally high efficiency and selectivity in CH 4 production, highlights the CuAu‐SAPNPs‐TiO 2 overarching superior photocatalytic properties. Consequently, this work underscores the potential of tailored SAs‐based systems for efficient and durable CO 2 reduction by reshaping surface adsorption dynamics and optimizing the thermodynamic behavior of the SAs.