Decoupling Substrate Adsorption and Reactive Oxygen Species Generation on Dual-Site Catalyst for Efficient Electrocatalytic C(sp3)-H Activation.

Electrocatalytic benzylic C(sp3)-H bond activation is one of the most effective and attractive means of hydrocarbon valorization; unfortunately, breaking the inherent low reactivity and similarity barriers of the C(sp3)-H bond remains a great challenge. In this paper, a dual-site MnO2/Co3O4/NC catalyst has been obtained for the electrocatalytic oxidation of lignin-sourced p-methoxy toluene (p-MT), which, excitingly, presents as high as 91.7% p-methoxy benzaldehyde (p-MBA) selectivity and 89.0% Faradaic efficiency (FE), along with a p-MT conversion of 93.4% under a mild catalytic environment, which ranks among the best of the state-of-the-art electrocatalysts ever reported. Additionally, different from previous reports, for the dual-site catalyst, it decouples the processes of substrate adsorption and reactive oxygen species (ROS) generation, with the former localized on the Co site and the latter on the Mn site, which avoids competitive adsorption and accelerated dissolution of active sites. More importantly, a *OOH catalytic pathway has been proposed and validated on the dual-site catalyst to play a dominant role in inhibiting the generation of various byproducts. Additionally, the dual-site catalyst exhibits broader applicability to the activation of different C(sp3)-H compounds than the single-site catalyst. This work provides a rational design for benzylic C(sp3)-H bond activation catalysts and offers in-depth insights into the electrocatalytic reaction pathway.