1 research outputs found
New Route of Acetylene Synthesis via Electrochemical Formation of Metal Carbides from CO<sub>2</sub> in Chloride Melts
Electrochemical conversion
of CO2 in high-temperature
molten salts provides a unique process for synthesizing materials
that cannot be obtained in low-temperature aqueous systems. In this
study, we propose a novel route to produce acetylene utilizing the
electrochemical reduction of CO2 in chloride melts. Acetylene
is generated by the reaction between water and metal carbides, which
are formed by the reduction of CO2 and cations in the melts.
We demonstrated the proposed process by electrochemical measurements
and quantitative gas analysis. To investigate the electrolytic system
suitable for forming Li2C2 and CaC2 as the metal carbides at high current efficiency, two types of melts:
LiCl–KCl–CaCl2–CaO melt at 723 K and
NaCl–KCl–CaCl2–CaO melt at 823 K,
and two types of electrodes: metallic electrodes (Fe, SUS304, SUS316,
Mo, Ta and Ti) and carbon electrodes (graphite, glassy carbon, and
highly oriented pyrolytic graphite) were used. It was found that acetylene
was obtained with a current efficiency of 68% by galvanostatic electrolysis
at −200 mA cm–2 on a Fe electrode in the
NaCl–KCl–CaCl2–CaO melt mixed with
7.0 mol % CaC2 under CO2 atmosphere. The CaC2 played a key role in preventing the dissolution of electrodeposited
metal carbides into the melts