Electrochemical Hydrogenation of Ethylene, Acetylene, and Ethylene-Acetylene Mixtures

The electrochemical hydrogenations of ethylene, acetylene, and ethylene‐acetylene mixtures were investigated on a platinum cathode as a function of applied potential (0.23V to −0.05V NHE), temperature (25°, 40°, and 55°C), and reactant partial pressures (0.01 to 1 atm) using 2N as the electrolyte. The principal products of the reactions were ethane and ethylene (from acetylene). Methane formation sometimes occurred at 40° and 55°C. The selective production of ethylene from acetylene or from an ethylene‐acetylene mixture generally increased with temperature, acetylene partial pressure, and potential. The hydrogenation of acetylene or ethylene‐acetylene is often controlled by the amount of electrically discharged hydrogen atoms at the cathode surface. The rate determining step in the hydrogenation of ethylene may be either mass transport of ethylene or surface kinetics.