Structure-Activity relationship and reaction mechanisms of the Cu/PSAC-Nx catalysts in the oxidation carbonylation of ethanol to diethyl carbonate

Cu catalysts supported on nitrogen-doped carbon with ultra-high specific surface area (2726 m 2 ⋅g −1 ) derived from peanut shells (PSAC-N x ) were fabricated and investigated in the oxidative carbonylation of ethanol to diethyl carbonate (DEC). The Cu/PSAC-N x catalysts exhibited superior catalytic performance with a maximum STY DEC of 3371 mg·g −1 ·h −1 , attributed to the higher surface Cu 0 and Cu + concentration. Both Cu 0 and Cu + acted as the active species that accelerated the activation of ethanol molecules and promoted the insertion of CO, respectively, in the DEC synthesis. Among the four by-products, diethoxyethane preferred to be generated at higher temperatures or extended reaction time, while acetaldehyde and ethyl acetate tended to be produced at the Cu 2+ species and ethyl formate was inclined to be created at a higher oxygen fraction. This work provided theoretical and experimental guidance for the rational design of efficient catalysts and the optimization of reaction conditions for the ethanol oxidative carbonylation to DEC.