Room-Temperature Electrocatalytic Dehydrogenation and Partial Fragmentation of n-Alkanes

Light alkenes are central building blocks in the chemical industry, yet their production from alkanes requires energy-intensive processes that generate substantial CO2 emissions and suffer from catalyst deactivation and overoxidation. In this work, we demonstrate that alkane dehydrogenation can be accomplished at ambient temperature and pressure by modulating the voltage applied to an electrocatalyst surface. Voltage manipulation provides real-time control over the adsorption and dehydrogenation of alkanes, as well as the potential-driven desorption of dehydrogenated adsorbates. By using a newly developed sensitive gas chromatographic (GC) analysis method, we were able to quantify the formation of 1-butene from n-butane, as well as the formation of a distribution of shorter chain alkanes and alkenes. We show that the product distribution depends on the potential applied during adsorption and is sensitive to both catalyst identity and electrolyte composition. Palladium suppresses C-C bond cleavage relative to platinum, and replacing protons with sodium cations increases 1-butene selectivity by promoting desorption over hydrogenation. To rationalize the observed product distribution, we propose a reaction mechanism supported by grand canonical density functional theory calculations. Together, these results reveal a new pathway for alkane dehydrogenation under ambient conditions and establish time-programmed electrochemical control as a promising tool for manipulating surface-catalyzed transformations of n-alkanes.