摘要
以γ-Al_2O_3为载体,采用常规浸渍法制备了负载型CuCl_2-KCl-LaCl_3三组分催化剂,并研究了其对乙烷氧氯化反应的催化性能.结果表明,该催化体系中乙烷的转化率较稳定,但随着反应时间的延长,氯乙烯的选择性和收率明显下降.XRD,N2吸附,TGA/DTA和XPS测试结果表明,随着反应的进行,催化剂中的活性物种Cu2+逐渐被还原成Cu+,并且积炭的产生使催化剂的比表面积和孔容积减小.活性物种Cu2+的减少及比表面积的降低是催化剂失活的主要原因.
The CuCl_2-KCl-LaCl_3/γ-Al_2O_3 catalyst was prepared by incipient wetness impregnation of γ-Al_2O_3 with CuCl_2·2H_2O, KCl and LaCl_3 solution and was used for the ethane oxychlorination. The catalyst was characterized by XRD, N_2 adsorption, TGA/DTA and XPS. The results indicate that the ethane conversion is stable in the system, but the selectivity and yield of ethylene chloride decrease obviously with the reaction time. The conversion of ethane is 92% to 97% and the initial total yield of ethylene and ethylene chloride is more than 80%. XPS spectra show that Cu 2+ species are gradually reduced to Cu+ with the reaction time and Cu+ species are hardly oxidized to Cu 2+ after reaction for 45 h because of the formation of KCl·CuCl_2. Specific surface area and pore volume of the catalyst decrease due to the carbon deposition, the amount of which is about 10.55%. The decrease of Cu 2+ species and surface area are the main reasons for the deactivation of the catalyst.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2005年第7期587-590,共4页
基金
吉林省科技厅资助项目(20020666).
关键词
氯化铜
氯化钾
氯化镧
氧化铝
乙烷
氧氯化
氯乙烯
copper chloride, potassium chloride, lanthanum chloride, alumina, ethane, oxychlorination, ethylene chloride
