Hydrogen Regenation of Sulfur Poisoned Platinum Catalysts

• Main Authors: Chang, Shi Lian, 張世亮
• Other Authors: Chang Jen Ray
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/36303121470590084369

碩士 === 國立中正大學 === 化學工程研究所 === 84 === The goals of this research were to investigate the kinetics and reaction mechanism of sulfur-poisoned Pt catalysts and aim at the improvement of the sulfur resistance of the catalysts. The catalytic test reactions were hydrogenation of tetralin containing sulfur ranging from 0 to 1000ppm. The reactions were carried out with a continuous fix bed reactor at 280℃ and 480psig. The effects of hydrogen regeneration operating conditions on the reactivation of the sulfur-poisoned catalysts were investigated by the catalysts unloaded from the reactor after the tests. Both fresh and the unloaded catalysts were characterized by CO chemisorption, fast Fourier transform infrared(FFT-IR) spectroscopy, temperature programmed reduction (TPR),electron probe micro analyzer (EPMA), and extended X-ray absorption fine structure(EXAFS). Together with the complementary characterization tools and the kinetic study, the following results were obtained: 1）The electron density and structure of the catalysts were varied with sulfur- poisoning; TPR,EPMA, and EXAFS results indicated that a metal migration during sulfur poisoning, while infrared characterizing CO adsorption ineicated that the electron density of sulfur poisoned platinum catalyst was decreased. 2)Kinetic of tetralin hydrogenation was varied from irreversible 1st order surface reaction to reactant-adsorption inhibition zero order reaction. 3）Infrared characterizing CO adsorption suggests that the electron density of sulfur poisoned platinum can be restore by hydrogen regeneration. On the contrary, the agglomeration of Pt particles induced from sulfur poisoning can*t be redispersed by simple hydrogenation, indicated by EXAFS results. This Pt agglomeration causes the irreversibility of the activity of a sulfur-poisoned catalyst.4）The addition of titanium to a platinum catalyst improve its sulfur resistance, and the catalyst has the best catalytic performance, when reduced at 530℃.