Direct synthesis of dimethyl carbonate from CO2 and methanol by supported bimetallic Cu-Ni/ZIF-8 MOF catalysts

Supported bimetallic Cu-Ni/ZIF-8 metal oxide framework (MOP) catalysts were synthesized for the production of dimethyl carbonate (DMC) from CO2 and methanol. The catalytic support material, zeolitic imidazolate framework-8 (ZIF-8), was prepared by solvothermal method using methanol (MeOH) as a solvent and then loaded with bimetallic Cu-Ni catalyst (1:1 by weight) via an incipient wetness impregnation. The support material and synthesized catalysts were first characterized using powder XRD, TGA, FT-IR, FE-SEM, TEM, BET and ICP-OES analysis. Then, the ZIF-8 supported bimetallic catalysts were tested for catalytic activity in the direct synthesis of DMC from CO2 and MeOH. Various parameters-metal loading content, reaction temperature, weight of catalyst loading and reaction time and their effects were investigated. The highest DMC yield (6.39%) and the highest MeOH conversion (12.79%) were achieved at 20 bar of CO2, 110 degrees C and 12 h using 0.7 g of 5%Cu-Ni/ZIF-8 catalyst. Under the optimized conditions, the catalyst was able to retain its catalytic performance up to 4 regeneration cycles. These results indicate that supported bimetallic Cu-Ni/ZIF-8 catalysts have a high potential for synthesis of DMC. (C) 2017 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.