Study on Wacker-type catalysts for catalytic synthesis of diethyl carbonate from ethyl nitrite route

CO catalytic synthesis of diethyl carbonate in vapor phase had been studied in a continuous flow system and a fixed-bed reactor at atmospheric pressure. PdCl2–CuCl2/AC (activated carbon) catalyst exhibited better catalytic activity compared with other Wacker-type catalyst systems using SiO2, α-Al2O3 and hexagonal mesoporous silica (HMS) as the carriers. The catalytic activity of the catalyst could be effectively improved by chemical pretreatment with H2. The suitable Pd content was 2.0 wt.% considering both factors of DEC production and DEC selectivity, and an optimum Pd/Cu mole ratio existed for catalytic activity, which was 1/2. The study also revealed that CH3OH was an excellent solvent for PdCl2–CuCl2/AC catalyst preparation.