The Catalytic Performance of Sol-Gel Alumina Supported Ti-Ce Catalysts for H2S Selective Oxidation to Elemental Sulfur


TAŞDEMİR H. M. , YAĞIZATLI Y. , YAŞYERLİ S. , YAŞYERLİ N.

INTERNATIONAL JOURNAL OF CHEMICAL REACTOR ENGINEERING, cilt.17, sa.5, 2019 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 17 Konu: 5
  • Basım Tarihi: 2019
  • Doi Numarası: 10.1515/ijcre-2018-0157
  • Dergi Adı: INTERNATIONAL JOURNAL OF CHEMICAL REACTOR ENGINEERING

Özet

In this study, alumina supported Ti-Ce catalysts (10 % by weight and Ti/Ce molar ratio is 4: 1) were prepared by using wet impregnation method and their catalytic activities were tested in H2S selective oxidation to elemental sulfur. The support alumina was synthesized by classical (SGC) and modified (SGM) sol-gel methods. The N-2 adsorption-desorption, XRD, XPS, EDS and FTIR techniques were used to characterize the synthesized catalysts. The N-2 adsorption-desorption isotherms showed that both catalysts have mesoporous structure. Only gamma-Al2O3 crystalline phase together with amorphous structure were observed in the XRD patterns. The pyridine adsorbed FTIR analyzes showed that 10 % Ti-Ce@SGC and 10 % Ti-Ce@SGM catalysts have the same Lewis acidity. The activity tests were carried out at 250 degrees C and with a stoichiometric feed ratio of O-2 to H2S being 0.5 for two different reaction times as 150 and 510 min. Complete conversion of H2S was obtained during 180 min. and 330 min. of reaction time over 10 % Ti-Ce@SGC and 10 % Ti-Ce@SGM, respectively. However, all catalysts showed very high sulfur selectivity. Sulfur deposition was detected over 10 % Ti-Ce@SGC catalyst both 150 and 510 min. of reaction time while it was observed after 510 min. of durability test over 10 % Ti-Ce@SGM catalyst. This can be the reason for the earlier loss of catalytic activity 10 % Ti-Ce@SGC than 10 % Ti-Ce@SGM.