An AuCl₃‐CuCl₂ catalyst on a Melamine‐modified Carbon Support with High Coke‐resistance for Acetylene Hydrochlorination

Abstract

According to the pilot‐scale test and characterizations, it showed that coke deposits, which were mainly composed of aromatic compounds polymerized by unsaturated hydrocarbons, were one of the key factors restricting the performance of AuCl3‐CuCl2 bimetallic catalyst in acetylene hydrochlorination. Thus, melamine was adopted to modify the activated carbon (AC) support to improve the catalytic performance of the AuCl3‐CuCl2 bimetallic catalyst. The effects on the properties of supports and catalysts were studied by XPS, BET, TPD characterizations, it showed that the modified support (MAC) had been introduced nitrogen‐containing functional groups successfully, which effectively increased the stability of the active components of Au3+ and Au+ on the gold‐based catalyst, as well as the capability to adsorb HCl and desorb C2H2. After a continuous reaction of the modified catalyst under industrial space velocity conditions for 720 h, the conversion of acetylene and selectivity to vinyl chloride both remain above 99 %. Then SEM showed that the carbon support via nitrogen modification could efficiently inhibit coke deposits reaction, which also helped improve the catalytic performance and stability of the catalyst.