Novel application of thermally expanded graphite as the support of catalysts for direct synthesis of DMC from CH 3OH and CO 2

Abstract

Novel Cu–Ni bimetallic catalysts supported on thermally expanded graphite (TEG) were prepared as an example to show the particular characteristics of TEG as a carbon support material. The structures of TEG and the synthesized Cu–Ni/TEG catalysts were characterized using BET, FTIR, TG, SEM, TEM, XRD and TPR techniques. The catalytic activities of the prepared catalysts were investigated by performing micro-reaction in the direct synthesis of dimethyl carbonate (DMC) from CH 3OH and CO 2. The experimental results indicated that the prepared Cu–Ni/TEG catalysts exhibited highly catalytic activity. Under the optimal catalytic conditions at 100 °C and under 1.2 MPa, the highest conversion of CH 3OH of 4.97% and high selectivity of DMC of 89.3% can be achieved. The highly catalytic activity of Cu–Ni/TEG in DMC synthesis can be attributed to the synergetic effects of metal Cu, Ni and Cu–Ni alloy in the activation of CH 3OH and CO 2 and the particular characteristics of TEG as a carbon support material.