催化学报

催化学报 ›› 2007, Vol. 28 ›› Issue (8): 720-724.

• 研究论文 • 上一篇    下一篇

PdCl2-CuCl2/Li-Al-O对CO低压气相合成碳酸二乙酯反应的催化性能

高晓晨,马新宾,王胜平,李振花   

  1. 天津大学化工学院绿色合成与转化教育部重点实验室, 天津 300072
  • 收稿日期:2007-08-25 出版日期:2007-08-25 发布日期:2011-08-19

Catalytic Performance of PdCl2-CuCl2/Li-Al-O for Synthesis of Diethyl Carbonate from CO and Ethyl Nitrite at Low Pressure

GAO Xiaochen, MA Xinbin*, WANG Shengping, LI Zhenhua   

  1. Key Laboratory for Green Chemical Technology of Education Ministry, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
  • Received:2007-08-25 Online:2007-08-25 Published:2011-08-19

PDF

903

被引次数

9

摘要： 采用LiNO3对γ-Al2O3进行改性,制备了以多孔锂铝尖晶石为载体,以Pd为活性组分的PdCl2-CuCl2/Li-Al-O负载型催化剂,并考察了催化剂对CO低压气相合成碳酸二乙酯(DEC)反应的催化性能,探讨了载体Li/Al比、改性浸渍方法、不同改性金属、Pd负载量和反应压力等因素对催化剂催化性能的影响. 结果表明,当n(Li)/n(Al)=0.2, 压力为0.3 MPa和温度为110 ℃时, DEC的时空收率可达到418 g/(L•h). 用LiNO3对γ-Al2O3改性后的催化剂载体表层具有LiAl5O8尖晶石结构,不同Li/Al比的催化剂载体的晶胞参数、晶胞体积略有不同. 采用双金属改性的催化剂载体表面由于结晶度较低不能形成“完全尖晶石结构”, 其催化活性较低. 随着催化剂表面活性组分PdCl2含量的增加,可有效提高产物DEC的时空收率; 锂铝尖晶石载体表面的酸性较低,有利于提高目标产物DEC的选择性.

关键词: 碳酸二乙酯, 一氧化碳, 亚硝酸乙酯, 氯化钯, 氯化铜, 氧化铝, 锂铝尖晶石, 负载型催化剂

Abstract: The catalytic performance of the PdCl2-CuCl2/Li-Al-O catalyst, with palladium as the active component and porous lithium alumina spinel (Li-Al-O) as the support, for vapor-phase synthesis of diethyl carbonate (DEC) from CO and ethyl nitrite was studied in a continuous fixed-bed reactor at low pressure. The Li-Al-O spinel support was synthesized by impregnation of γ-Al2O3(2-3 mm) with aqueous LiNO3 solution. Under the mild reaction conditions of 5%CO-20%EtONO-75%N2, GHSV=2500h-1, 0.3 MPa, and 110 ℃, the CO conversion was 40% and the space time yield of DEC was 418 g/(L•h). The perfectly close-packed spinel structure could be obtained because of the lithium ions that entered the vacancy of γ-Al2O3. The Li-Al-O catalyst support had no strong acid sites, and the catalyst had stable palladium chloride, both of which were favorable for the DEC synthesis reaction.

Key words: diethyl carbonate, carbon monoxide, ethyl nitrite, palladium chloride, copper chloride, alumina, Li-Al-O spinel, supported catalyst