Sulfidation of nickel- and cobalt-promoted molybdenum–alumina catalysts using a radioisotope 35S-labeled H2S pulse tracer method

Autor:	Toshiaki Kabe, Weihua Qian, Yasuo Aoyama, Atsushi Ishihara
Rok vydání:	2000
Předmět:	inorganic chemicals organic chemicals Process Chemistry and Technology Nickel oxide Inorganic chemistry Sulfidation chemistry.chemical_element Catalysis Nickel chemistry Transition metal Molybdenum heterocyclic compounds Cobalt oxide Cobalt
Zdroj:	Applied Catalysis A: General. 196:103-110
ISSN:	0926-860X
DOI:	10.1016/s0926-860x(99)00454-8
Popis:	The sulfidation state in a series of nickel- and cobalt-promoted Mo/Al 2 O 3 catalysts was investigated using 35 S radioisotope pulse tracer methods (RPTM). Several pulses of 35 S -labeled H 2 S ([ 35 S ]H 2 S) were introduced into catalysts in a nitrogen stream until the radioactivity in the recovered pulse approached the radioactivity of the introduced pulse. From the amount of [ 35 S ]H 2 S introduced, the amount of sulfur accumulated on the catalyst was estimated. The amounts of sulfur accumulated on the catalysts increased with increasing temperature for all catalysts and the cobalt-promoted catalysts showed features similar to those of the nickel-promoted catalysts. It was found that the sulfided states of the catalysts close to the stoichiometric states, where Ni, Co and Mo are present as NiS, Co 9 S 8 and MoS 2 , was attained at 400°C for all catalysts. Moreover, it was suggested that only molybdenum was sulfided below 300°C; the sulfidation of nickel oxide and cobalt oxide in the Ni– or the Co–Mo/Al 2 O 3 catalyst is more difficult at lower temperatures and the sulfidation of nickel and cobalt species occurs only at higher temperatures (above 300°C).
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::c9077854ea738609d09653b335367ddb https://doi.org/10.1016/s0926-860x(99)00454-8 Zobrazit plný text záznamu Full Text from ScienceDirect