Electrocatalytic hydrogenation of organic compounds using a nickel sacrificial anode

An electrochemical method, aimed at the hydrogenation of organic substrates, was developed, using a nickel sacrificial anode. The electrochemical system included an iron cathode with deposited nickel and presented good electrochemical efficiency. Some different parameters such as co-solvent, current density, supporting electrolyte and pH were studied to obtain the maximum efficiency for the process. An elevated cell voltage was observed (2.3 V) when 0.2 M NH4Ac was used as supporting electrolyte, whereas in NH4Cl experiments could be carried out at a low potential (1.3 V). Electrocatalytic hydrogenation (ECH) of organic substrates showed that non-conjugated olefins (cyclohexene and geraniol) were not reactive, while conjugated substrates (2-cycloexen-1-one, benzaldehyde, acetophenone, styrene, trans-trans-2,4-hexadien-1-ol, 1,3-cyclohexadiene, citral and linalool) showed good reactivity and selectivity in some cases. A direct correlation was observed between the electrochemical efficiency, substrate concentration and current density.