Understanding the interplay between electrocatalytic C(sp3)‒C(sp3) fragmentation and oxygenation reactions

Achieving the selective electrocatalytic activation of C(sp³)–C(sp³) and C(sp³)−H bonds is key to enabling the electricity-driven synthesis of chemicals, the sustainable upgrading of plastics and the development of fuel cells operating on energy-dense liquid fuels. When exposed to electrodes under oxidative bias, hydrocarbons undergo both C–C bond fragmentation and oxygenation. Currently, we lack control over the bifurcation of these pathways. Here we provide insights into the complex network of alkyl transformation reactions, showing that under oxidizing potentials, adsorbed butane transforms to adsorbed CH_x fragments, which can be desorbed as methane before oxidation to adsorbed CO. Identifying the branchpoint between C‒C fragmentation and oxygenation allowed us to steer selectivity by applying pulsed potentials tailored to the desorption potential of specific adsorbates and the kinetics of intermediate oxidation. Our findings provide design criteria for improved fuel cell catalysts and open the door to selective C‒C cleavage in electrosynthetic pathways.