Synthesis of C₄ Olefins from Acetylene over Supported Copper Catalysts

Abstract

Conversion of acetylene to C4 olefins enables on‐purpose synthesis of C4 olefins using abundant natural gas resource due to acetylene can be synthesized from methane or ethane. In this study, Cu‐based catalysts supported on SiO2, ZSM‐5 and mordenite (MOR) were tested for acetylene hydrodimerization. Effect of promoters including Ru, Ga, Ag and Pd on the acetylene conversion and C4 olefins selectivity are investigated. The structures of these catalysts were characterized by TEM, XRD, BET, H2‐TPR, NH3‐TPD and XPS measurements. Results showed that temperature, pressure and hydrogen partial pressure had positive effect on acetylene conversion. In the presence of Ru promotor, 100 % acetylene conversion and 87 % selectivity to C4 olefins were achieved over Cu/MOR catalyst under conditions of 0.1 MPa and 200 °C. The mechanistic aspect of acetylene hydrodimerization was elucidated where the C4 intermediate was formed by the reaction between [Cu]−C2H2 π‐complex and [Cu]−C2H2 σ‐complex which were transformed to 1,3‐butadiene and butene.

Light Olefins from Acetylene under Pressurized Conditions

“…In a previous study, we demonstrated the reaction of acetylene with ethylene to form butadiene, using commercially available molecular catalysts dissolved in a suitable solvent, revealing the possibilities opened up by the high reactivity of acetylene. The use of liquid media and molecular catalysts has so far been the preferred way of converting acetylene, , while solid-catalyzed reactions of gaseous acetylene have only rarely been studied. − A recent study reported the formation of C 4 -olefins from acetylene over copper confined in the pores of metal–organic frameworks. However, the information in this manuscript is insufficient to assess catalytic activity.…”