Influence of Surface Acidity of Y Zeolites on the Adsorption of Organic Molecules by <em>In situ</em> Fourier Transform Infrared Spectroscopy

Abstract

The surface acidity of Y-type zeolites (HY and NaY) modified by solid state ion exchange (SSIE) and liquid phase ion exchange were characterized by in situ Fourier transform infrared (FTIR) spectroscopy using pyridine as the probe molecule (Py-FTIR). The adsorption of single probe molecules (thiophene, cyclohexene and benzene) and double probe molecules (thiophene and cyclohexene, thiophene and benzene) compared with sorbents were studied using in situ FTIR spectroscopy. The results indicated that the Bronsted acid (B acid) of HY (L-CeY) is the catalytic center of cyclohexene dimerized alkenyl carbenium ions and thiophene oligomerization, while the Lewis acid (L acid) is the major center of adsorption of thiophene, cyclohexene, and benzene. In addition, there is strong chemisorption and competitive adsorption of cyclohexene and thiophene, which provides evidence for the poor performance [Article] doi: 10.3866/PKU.WHXB201303183 www.whxb.pku.edu.cn 物理化学学报(Wuli Huaxue Xuebao) Acta Phys. -Chim. Sin. 2013, 29 (6), 1273-1280 June Received: January 2, 2013; Revised: March 18, 2013; Published on Web: March 18, 2013. ∗Corresponding author. Email: lsong56@263.net; Tel/Fax: +86-24-56860658. The project was supported by the National Natural Science Foundation of China (20976077, 21076100), Major Program of Petroleum Refining of Catalyst of Petro China Company Limited (10-01A-01-01-01), Innovation Team of Liaoning Province Colleges, China (200T110), and Construction Project of Liaoning Province High-end Talent Team. 国家自然科学基金(20976077, 21076100),中国石油天然气股份有限公司炼油催化剂重大专项(10-01A-01-01-01),辽宁省高校创新团队项目 (200T110)及辽宁省高端人才队伍建设项目资助 C Editorial office of Acta Physico-Chimica Sinica 1273 Vol.29 Acta Phys. -Chim. Sin. 2013 of removing sulfur. The S-CeY zeolite has abundant of weak Lewis acid sites. The sorbent is good at absorbing thiophene, while the influence of the competition adsorption of cyclohexene was not predominately. As to NaY zeolite, there is no preference for adsorption of thiophene, cyclohexene and benzene.