Structure and activity of a CoMo/Al2O3 catalyst upon modification by gamma irradiation

✍ Scribed by Ch. Vladov; L. Petrov; B. Ytua; L. Topalova

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 552 KB
• Volume: 94
• Category: Article
• ISSN: 0926-860X
• DOI: 10.1016/0926-860x(93)85008-d

✦ Synopsis

The activity of a commercial CoMo/A1,03 catalyst was examined in the reaction of thiophene hydrodesulfurization.

The catalytic measurements were performed in a gradientless flow circulating system at atmospheric pressure. It was found that preliminary irradiation of the catalyst by gamma rays gives rise to a considerable increase in catalytic activity and selectivity. The enhancement of activity was retained even after regeneration of the catalyst. As a result of the irradiation some of the tetrahedrally coordinated Co'+ ions were transformed into species with another environment.

In addition, upon irradiation some of the Mo6+ ions were reduced to Mo5+ ions and it is suggested that defects are formed on the catalyst surface. Changes in composition and structure of the catalyst samples, which were preserved even after regeneration, are associated with the changes in the catalytic properties.