(569cx) Highly Selective Electrocatalytic Semihydrogenation of Acetylene to Ethylene with Suppressed 1,3-Butadiene Formation

Ethylene is an important feedstock in petrochemical industry for producing commodity chemicals. Traditional methods to produce ethylene such as steam cracking and thermocatalytic hydrogenation of acetylene are limited to the high energy consumption and environmental detriment. Electrocatalytic hydrogenation of acetylene to ethylene in aqueous electrolytes, however, provides an energy-efficient and environmental-friendly approach to ethylene production under ambient conditions. Yet, it is challenging to suppress competitive evaluation of hydrogen and 1,3-butadiene by-products and thus achieve high efficiency and selectivity of ethylene. Herein, Cu NP/FeNC-10 catalyst was prepared and exhibited a highest ethylene faradaic efficiency of 98.87% at 160 mA cm^-2 and the ethylene selectivity up to 94.2% at 200 mA cm^-2. The electrochemical impedance spectroscopy (EIS) test confirmed that FeNC in Cu NP/FeNC-10 facilitated the electron transfer process, which could further explain the excellent electrocatalytic acetylene semihydrogenation performance. The kinetic isotope effect (KIE) test further affirmed that FeNC in Cu NP/FeNC-10 accelerated the proton transfer process and inhibited the formation of 1,3-butadiene. These results provided a feasible method for efficient and highly selective conversion of acetylene to ethylene under mild conditions. Besides, the fossil resources were replaced by electrical energy and water was used as hydrogen source to achieve the conversion of acetylene to ethylene, which was conducive to sustainable development. Moreover, a Zn-C₂H₂ battery based on Cu NP/FeNC-10 cathode was constructed and exhibited a peak power density of 2.16 mW cm^-2 occurred at 4.8 mA cm^-2 and a FE of ethylene over 90% within a wide range of current densities in discharge process, suggesting its potential application in environment-friendly energy conversion and storage.