Graphene supported Cu nanoparticles as catalysts for the synthesis of dimethyl carbonate: Effect of carbon black intercalation

Abstract

Reduced graphene oxide (rGO) intercalated with a carbon black (CB) supported copper catalyst (Cu/rGO-CB) was employed in the synthesis of dimethyl carbonate (DMC) via liquid-phase oxidative carbonylation of methanol. The conversion of methanol and the space-time yield of DMC (STYDMC) over Cu/rGO-CB reached 5.6% and 2757mg/(gh), higher than over a Cu/rGO catalyst, 4.7% and 2334mg/(gh), respectively. The characterization indicates that CB particles, acting as spacers, ensured the high utilization of graphene layers and enhanced the interaction between Cu and the support, and the oxygen containing groups on the surface of CB play an important role in stabilizing Cu clusters. In comparison with Cu/rGO, the loss of copper concentration in Cu/rGO-CB is significantly decreased, from 15.37% to 1.96%. Catalyst reusability tests show that Cu/rGO-CB could be reused five times without almost any catalytic activity loss, implying distinct enhanced catalytic stability compared to the Cu/rGO catalyst.