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利用液相离子交换法制备了CuY分子筛,并用X射线光电子能谱分析(XPS)对Cu元素进行了价态表征,用原位傅里叶转换红外(in-situ FTIR)和氨气程序升温脱附(NH_3-TPD)技术对其进行了酸性表征。同时,以噻吩和环己烯为探针分子,Cu Y分子筛为吸附剂,研究了环己烯对噻吩在CuY分子筛B酸中心上吸附的影响机制。实验结果显示,CuY分子筛表层的Cu离子主要以Cu~+为主,其表面酸性主要由中强B酸和L酸组成。与稀土离子不同的是,铜离子的存在抑制了噻吩或环己烯在B酸中心上的聚合反应。因此,环己烯主要通过与噻吩的竞争吸附影响噻吩在CuY分子筛B酸性位上的吸附。
CuY molecular sieve was prepared by liquid-phase ion exchange method. The Cu element was characterized by X-ray photoelectron spectroscopy (XPS). The in-situ FTIR and ammonia temperature were used to characterize the Cu element. Attached (NH_3-TPD) technology for its acidic characterization. At the same time, using thiophene and cyclohexene as the probe molecules and Cu Y zeolite as the adsorbent, the influence mechanism of cyclohexene on the adsorption of thiophene on the acid site of CuY molecular sieve B was studied. The experimental results show that the Cu ions in the surface of CuY zeolite are mainly Cu ~ +, and the surface acidity is mainly composed of medium B acid and L acid. Unlike rare earth ions, the presence of copper ions inhibits the polymerization of thiophene or cyclohexene at the center of B acid. Therefore, cyclohexene mainly affects the adsorption of thiophene on the acidic sites of CuY molecular sieve B by competitive adsorption with thiophene.