Oxygen chemisorption: Its relationship to hydrotreating activity of alumina-supported nickel-molybdenum catalysts

• Published in: Journal of catalysis Vol. 90; no. 1; pp. 10 - 16
• Main Authors: Millman, W.S., Bartholomew, C.H., Richardson, R.L.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.01.1984; Elsevier
• Subjects: Catalysis; Catalysts: preparations and properties; Catalytic reactions; Chemistry; Exact sciences and technology; General and physical chemistry; General. Nomenclature, chemical documentation, computer chemistry; Theory of reactions, general kinetics; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Oxygen; Adsorption; Alumina; Supported catalyst
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/0021-9517(84)90078-2

Oxygen chemisorption capacities of sulfided alumina-supported NiMo catalysts were determined by pulse and static adsorption methods at ambient temperatures. The pulse method resulted in lower chemisorption uptakes compared to the static method. Static to pulse uptake ratios of 2.12 to 3.03 were observed for freshly sulflded catalysts while values of 1.70 to 1.92 were obtained for catalysts which had been tested for hydrodenitrogenation (HDN) activity. A general trend of increasing O 2 chemisorption uptake with increasing activity for removal of basic nitrogen, total nitrogen, and sulfur was observed for NiMo catalysts. However, because variations in the specific O 2 chemisorption capacity per activity unit among these three reactions were small (±10%), it does not appear that O 2 adsorption is selective for the active sites of any one reaction, rather, it is probably proportional to the sum of these different sites. Comparison of the O 2 adsorption capacity with the activity data (reproducibility ±3%) indicates the use of O 2 adsorption can distinguish large differences in catalyst activity (>25%) but not smaller differences.