Propane dehydrogenation to propylene represents a key route for replacing traditional petroleum-based processes. However, conventional Pt-based catalysts are limited by an intrinsic scaling relationship between C–H activation capability and propylene adsorption strength, such that enhancing catalytic activity would lead to the reduction of propylene selectivity and even coking. Herein, we demonstrate that the cooperative frustrated Ga···N and Ga···Ga pairs on GaN can effectively break the linear scaling relationship. The frustrated Lewis pairs (Ga···N) facilitate the rate-limiting step of the first C–H bond dissociation in propane, with a Gibbs free energy of activation of 1.63 eV, slightly lower than that on the conventional Pt–Sn catalyst (1.81 eV). The frustrated metal pairs (Ga···Ga) are responsible for 1-propyl dehydrogenation, exhibiting weak propylene adsorption and further suppressing the deep dehydrogenation of propylene. Kinetic Monte Carlo simulations based on the overall reaction network indicate that GaN exhibits excellent catalytic activity, with a turnover frequency of 18.33 s–1 for propylene production, significantly higher than that of Pt-based catalysts. This study not only elucidates how the cooperation of frustrated Ga···N and Ga···Ga pairs breaks the linear scaling relationship, but also provides insights for the design of novel catalysts for propane dehydrogenation.
Yu et al. (Wed,) studied this question.