On July 22, from the Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences, the team of researcher Zhang Tierui made progress in the study of acetone reduction to ethylene at room temperature. Proposed a method based on gas. solid The new electrocatalytic acetylene reduction reaction strategy of liquid three-phase interface is expected to replace the existing thermal catalytic acetylene hydrogenation technology and be applied to the purification process of industrial ethylene raw gas.

According to reports, the room temperature acetylene electric reduction strategy developed by the research team, the power cost required for converting low-concentration acetylene into ethylene is less than 0.5% of the ethylene market price, and compared with traditional thermal catalysis in energy and atomic economy, showing outstanding advantages. In addition, the team solved the problem of traditional solid catalysis. Liquid two-phase electrocatalytic system interface diffusion mass transfer scientific problems, acetylene reduction current density increased by more than 60 times, Faraday efficiency increased by about 40%, so that the electrocatalytic acetylene reduction of a number of performance test results reached or even exceeded the traditional thermal catalytic hydrogenation system reported the highest value, is electrochemistry in the future chemical industry is expected to replace the thermochemical process is another landmark research example.

Zhang Tierui said that the traditional thermal catalytic acetylene hydrogenation technology usually needs to be carried out at a temperature above 100 бу C, and the introduction of excessive hydrogen is required, which is not only easy to cause excessive hydrogenation of ethylene, but also lead to additional gas separation operations. Therefore, the selective catalytic conversion of acetylene at lower temperatures, while avoiding the introduction of additional gas impurities, is still facing challenges. The room temperature selective conversion of low concentration acetylene in

ethylene rich atmosphere depends on the redesign of catalytic materials and catalytic systems." In view of this, combined with the research foundation in catalytic materials and electrochemistry, the research group conducted checkerboard search and test from the aspects of material preparation, reactor design, parameter regulation and other aspects, and finally found the optimal test conditions of copper based interfacial structure catalytic material, thin layer gas diffusion microfluidic reactor, alkaline electrolyte and so on. Zhang Tierui introduced that.

It is understood that the research team uses the Cu/Cu?O interface structure nanocatalytic material formed by in-situ transformation of layered bimetallic hydroxide (LDH), replaces hydrogen with water as the proton source, and achieves the selective reduction of low concentration acetylene in an ethene-rich atmosphere at room temperature. The acetylene conversion rate reaches 99.9%, and the ethylene selectivity is greater than 90%. And reduce the acetylene concentration from 5000ppm to below 1ppm. All the indexes of the electrocatalytic acetylene reduction reaction system (acetylene conversion, ethylene selectivity, residual hydrogen, reaction temperature, specific activity) have reached or exceeded the optimal value reported by hot catalytic acetylene hydrogenation.

In particular, industrial ethylene raw materials come from the cracking of hydrocarbons such as naphtha, and the cracking products inevitably contain 0.5% to 2.0% acetylene impurities. Acetylene impurities can poison the Ziegler that is later used in ethylene polymerization. Natta catalyst, affecting the quality of polymer products. Therefore, it is necessary to reduce the concentration of acetylene impurities to the ppm level before polymerization.

Next, the research team will further study the relationship between the structure of catalytic materials and acetylene electroreduction activity, and carry out research in solid electrolyte, modular electrochemical acetylene reduction system, etc., to promote the commercial application of electrocatalytic alkyne hydrogenation, ethylene purification and other technical routes.