Coherently Coupled Frustrated Lewis Pairs in In2O3−x Nanoclusters for Selective CO2 Photoreduction to CH4

Abstract Co‐catalysts integration presents unique opportunities to enhance photoactivity, yet selectivity control and mechanistic understanding within multistep reactions remain fundamental challenges hitherto. In this study, a reshaped kinetic landscape is demonstrated over coherently coupled surface frustrated Lewis pairs (FLPs) on carbon nitride matrix, which mediates directed CO 2 ‐to‐CH 4 conversion with a selectivity of 65.3% (electron basis). The hydrogen‐bonded interface fosters intimate electronic coupling, generating built‐in electric fields that facilitate cascade charge transfer processes. Particularly, exceptionally robust FLPs sites were identified within the sub‐nanosized In 2 O 3− x nanoclusters, in contrast to easily deactivated counterparts in oversized crystalline structures. These enduring FLPs sites confer privileged adaptive binding with CO 2 and mutative C1 intermediates. Correlated in situ infrared and mass spectroscopic analyses track the formation of FLPs‐CO 2 adducts and highlight the predominance of formate (HCOO − ) pathway, surpassing competitive CO evolution. This work opens inspiring prospects for exploring multielectron photochemistry and achievable metrics through distinctive FLPs topologies on sub‐nanostructures.