| Summary: | Such is the case of acetylene (C2H2), an essential hydrocarbon with a plethora of applications. This highly flammable gas is used for welding, industrial cutting, metal hardening, heat treatments, and other industrial processes. In addition, it is an important precursor in the production of synthetic resins and plastics, including PVC. Since the production of C2H2 requires fossil fuels as feedstock, a more environmentally friendly synthesis route is urgently needed. Against this backdrop, a research team based on an academia–industry collaboration between Doshisha University and Daikin Industries, Ltd., Japan, has been developing a new and promising strategy to produce C2H2 using carbon dioxide (CO2) and water (H2O) as raw materials. Their latest study, which included Assistant Professor Yuta Suzuki from Harris Science Research Institute and Professor Takuya Goto from the Department of Science of Environment and Mathematical Modeling of Graduate School of Science and Engineering, both at Doshisha University, and Tomohiro Isogai from Technology and Innovation Center at Daikin Industries Ltd., is published in ACS Sustainable Chemistry & Engineering. The proposed approach is based on the electrochemical and chemical conversion of CO2 into C2H2 by using high-temperature molten salts, namely chloride melts. One key aspect of the process is that it leverages metal carbides, which are solids composed of carbon atoms and metal atoms, as a pivot point in the conversion. "In our strategy, CO2 is first converted to metallic carbides such as CaC2 and Li2C2, which deposit onto one of the electrodes," explains Dr. Suzuki. "Then, these metal carbides react with H2O, generating C2H2 gas." To achieve higher energy efficiency out of this method, the team had to test various configurations, including different electrode materials and molten salt compositions. After a series of comprehensive experiments, including cyclic voltammetry, carbon... |