Novel Cu-Fe bimetal catalyst for the formation of dimethyl carbonate from carbon dioxide and methanol

Abstract

A novel Cu-Fe bimetal supported catalytic system was prepared and applied to the direct dimethyl carbonate (DMC) formation from methanol and CO 2. The prepared catalysts were characterized by means of temperature-programmed reduction (TPR), X-ray powder diffraction (XRD), laser Raman spectra (LRS), X-ray photoelectron spectroscopy (XPS) and temperature programmed desorption (TPD). Metallic Cu, Fe and oxygen deficient Fe 2O3-x (0 < x < 3) were formed during the reduction and activation step. The supported Cu-Fe bimetal catalysts exhibited good catalytic activity and high stability for the direct DMC formation. Under the reaction conditions at 120 °C and 1.2 MPa with space velocity of 360 h -1, the highest methanol conversion of 5.37% with DMC selectivity of 85.9% could be achieved. The high catalytic performance of the Cu-Fe bimetal catalysts in the DMC formation could be attributed to the interaction of base sites functioned by metallic Cu and Fe with acid sites provided by oxygen deficient Fe2O3-x (0 < x < 3) in the activation of methanol and CO2. The moderate concentration balance of acid and base sites was in favor of DMC formation. © 2012 The Royal Society of Chemistry.