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-h-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.