能源化学(英文版)

能源化学(英文) ›› 2019, Vol. 28 ›› Issue (2): 40-49.DOI: 10.1016/j.jechem.2018.02.001

• Preface • 上一篇    下一篇

Selective hydrogenation of acetylene on SiO2-supported Ni-Ga alloy and intermetallic compound

Lei Wang, Fengxu Li, Yanjun Chen, Jixiang Chen   

  1. Tianjin Key Laboratory of Applied Catalysis Science and Technology, Department of Catalysis Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China
  • 收稿日期:2017-12-13 修回日期:2018-01-27 出版日期:2019-02-15 发布日期:2019-02-15
  • 通讯作者: Jixiang Chen
  • 基金资助:

    This work was supported by the National Natural Science Foundation of China (21576193).

Selective hydrogenation of acetylene on SiO2-supported Ni-Ga alloy and intermetallic compound

Lei Wang, Fengxu Li, Yanjun Chen, Jixiang Chen   

  1. Tianjin Key Laboratory of Applied Catalysis Science and Technology, Department of Catalysis Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China
  • Received:2017-12-13 Revised:2018-01-27 Online:2019-02-15 Published:2019-02-15
  • Contact: Jixiang Chen
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (21576193).

摘要： Ni/SiO2 and bimetallic NixGa/SiO2 catalysts with different Ni/Ga atomic ratios (x=10~2) were investigated for the selective hydrogenation of acetylene. It was found that NixGa/SiO2 showed higher selectivity to ethylene than Ni/SiO2. This is attributed to the formation Ni-Ga alloy and Ni3Ga intermetallic compound (IMC) where there was a charge transfer from Ga to Ni, which is favorable for reducing the adsorption strength and amount of ethylene on Ni atoms. As a result, the over-hydrogenation, the C-C bond hydrogenolysis and the polymerization were suppressed, and subsequently the selectivity to ethylene was enhanced. With the decrease of Ni/Ga atomic ratio, the activity and stability of the NixGa/SiO2 catalysts increased first and then decreased, while the ethylene selectivity tended to increase. Ni5Ga/SiO2 exhibited the best performance. Under the conditions of 180℃, 0.1 MPa, and a reactant (1.0 vol% acetylene, 5.0 vol% H2 and 94 vol% N2) with the space velocity of 36,000 mL h-1 g-1, the acetylene conversion maintained at 100% on Ni5Ga/SiO2 during 120 h time on stream and the selectivity to ethylene was 75%～81% after reaction for 68 h. It was also found that the formation of Ni-Ga alloy and Ni3Ga IMC suppressed the incorporation of carbon to form NiCx, subsequently enhancing the catalyst stability. Additionally, with increasing the Ga content, the catalyst acid amount and strength tended to increase, which promoted the polymerization and carbon deposition and so the catalyst deactivation.

关键词: Selective hydrogenation, Acetylene, Ni-Ga alloy, Ni3Ga intermetallic compound

Abstract: Ni/SiO2 and bimetallic NixGa/SiO2 catalysts with different Ni/Ga atomic ratios (x=10~2) were investigated for the selective hydrogenation of acetylene. It was found that NixGa/SiO2 showed higher selectivity to ethylene than Ni/SiO2. This is attributed to the formation Ni-Ga alloy and Ni3Ga intermetallic compound (IMC) where there was a charge transfer from Ga to Ni, which is favorable for reducing the adsorption strength and amount of ethylene on Ni atoms. As a result, the over-hydrogenation, the C-C bond hydrogenolysis and the polymerization were suppressed, and subsequently the selectivity to ethylene was enhanced. With the decrease of Ni/Ga atomic ratio, the activity and stability of the NixGa/SiO2 catalysts increased first and then decreased, while the ethylene selectivity tended to increase. Ni5Ga/SiO2 exhibited the best performance. Under the conditions of 180℃, 0.1 MPa, and a reactant (1.0 vol% acetylene, 5.0 vol% H2 and 94 vol% N2) with the space velocity of 36,000 mL h-1 g-1, the acetylene conversion maintained at 100% on Ni5Ga/SiO2 during 120 h time on stream and the selectivity to ethylene was 75%～81% after reaction for 68 h. It was also found that the formation of Ni-Ga alloy and Ni3Ga IMC suppressed the incorporation of carbon to form NiCx, subsequently enhancing the catalyst stability. Additionally, with increasing the Ga content, the catalyst acid amount and strength tended to increase, which promoted the polymerization and carbon deposition and so the catalyst deactivation.

Key words: Selective hydrogenation, Acetylene, Ni-Ga alloy, Ni3Ga intermetallic compound