The efficient and selective electrocatalytic hydrogenolysis of C-O bonds is highly desired for producing chemicals and fuels from biomass. Although protons are known to play a critical role in C-O activation, the effect of catalyst supports on proton transfer remains insufficiently understood. Herein, using the Eu2+/Eu3+ redox mediator and Pd/TiO2 as the catalyst, we achieved >99% conversion and selectivity in the hydrogenolysis of benzyl phenyl ether, exhibiting 7-fold activity of Pd/C under a dilute acidic environment. We demonstrate that, compared to carbon supports, TiO2 facilitates proton transfer to Pd active sites, creating a localized high proton concentration. More importantly, protonation of the ether linkage (C-O-C) reduces the electron transfer energy barrier for hydrogenolysis, thereby enhancing the Faradaic efficiency. These findings offer valuable insights for designing electrocatalysts for efficient C-O bond cleavage and establish a practical platform for electrocatalytic biomass valorization.
Chang et al. (2026) studied this question.