Photocatalyst Design with an Electrical-Polarization-Ability Descriptor for Exclusive C–H Bond Activation in Methanol

Photocatalysis is increasingly used as an effective tool for green synthesis, where the precise activation of specific chemical bonds is crucial for achieving high selectivity. Descriptor-based scaling has emerged as an effective method for assessing structure-activity relationships in heterogeneous photocatalysis; however, selectivity-related descriptors remain scarce. Here, we introduce the "electrical-polarization-ability (δ)" as a novel descriptor that considers the polarity of the active site and its surrounding microenvironment, incorporating electrical, structural, and orbital contributions. δ allows for the quantification of surface-adsorbate interactions across various semiconductors. This descriptor is evaluated in the photocatalytic activation of C-H or O-H bonds in methanol, where preferential C-H bond activation leads to oxidative coupling to yield ethylene glycol (EG), an important bulk chemical. δ captures selectivity trends among experimentally reported semiconductors with diverse properties and aids in the rational design of carbon-doped hexagonal boron nitride (C-<i>h</i>-BN), achieving an exceptional EG selectivity of 98.9%. Our work underscores the promising potential to accelerate innovation in green synthesis through descriptor-guided selective photocatalyst design.