Search

Ethylene is a widely used industrial raw material. Due to petroleum resources shortage, direct hydrogenation of acetylene by calcium carbide to ethylene has attracted much attention. Accordingly, Ni/AC-N-x catalyst was synthesized by a simple impregnation method to investigate how the support's N-content influenced the catalyst performance. We studied the support-metal interactions by temperature-programmed reduction and X-ray photoelectron spectroscopy and the changes were studied. The acetylene conversion remained at ~96% for 10 h at 200 °C under a high gas hourly space velocity of 4000 mL·g−1·h−1 over Ni/AC-N-0.5 while over Ni/AC, the acetylene conversion decreased to 29% in 10 h. Unlabelled Image • Nitrogen-doped activated carbon support was synthesized by a simple impregnation method • The stability of the Ni catalyst was improved with nitrogen doped carbon as support • The enhancement of the Ni/AC-N was attributed to interaction between the Ni and AC-N support [ABSTRACT FROM AUTHOR]

Ethylene is an important chemical raw material and with the increasing consumption of petroleum resources, the production of ethylene through the calcium carbide acetylene route has important research significance. In this work, a series of bimetallic catalysts with different Cu/Ni molar ratios are prepared by co-impregnation method for the hydrogenation of calcium carbide acetylene to ethylene. The introduction of an appropriate amount of Cu effectively inhibits not only the formation of ethane and green oil, thus increasing the selectivity of ethylene, but also the formation of carbon deposits, which improves the stability of the catalyst. The ethylene selectivity of the Ni–Cu bimetallic catalyst increases from 45% to 63% compared with the Ni monometallic counterpart and the acetylene conversion still can reach 100% at the optimal conditions of 250 °C, 8000 mL·g−1·h−1 and V(H2)/V(C2H2) = 3. X-ray diffraction and transmission electron microscopy confirmed that the metal particles were highly dispersed on the support, High-resolution transmission electron microscopy and H2-Temperature programmed reduction proved that there was an interaction between Ni and Cu, combined with X-ray photoelectron spectroscopy and density functional theory calculations results, Cu transferred electrons to Ni changed the Ni electron cloud density in NiCux catalysts, thus reducing the adsorption of acetylene and ethylene, which is favorable to ethylene selectivity. [ABSTRACT FROM AUTHOR]