Commercial carbon fibers can be used as electrodes with high conductive surfaces in reduced devices. Oxidative treatment of such electrodes results in a chemically robust material with high catalytic activity for electrochemical proton reduction, enabling the measurement of quantitative faradaic yields (>95%) and high current densities. Combination of experiments and theoretic calculations reveals that the presence of carboxylic groups triggers such electro-catalytic activity in a bioinspired manner. Analogously to the known Hantzsch esters, the oxidized carbon fiber material is able to transfer hydrides, which can react with protons generating H2 or with organic substrates resulting in their hydrogenation. A plausible mechanism is proposed based on DFT calculations on model systems.