Sintering of nickel particles supported on gamma-alumina in ammonia
Artikel i vetenskaplig tidskrift, 2002

Sintering of nickel on gamma-alumina in hydrogen, ammonia, ammonia + hydrogen and ammonia + nitrogen was investigated isocoric in the temperature range 483 to 523 K. The sintering process was followed by hydrogen chemisorption, specific surface area measurements, X-ray diffraction and transmission electron microscopy. After exposure to ammonia + hydrogen, hydrogen chemisorption revealed a fast decline of the nickel surface area. The results from X-ray diffraction and transmission electron microscopy are consistent with the result from the chemisorption experiments. The BET analysis showed that there are no losses of the total surface area. The sintering rate was significantly slower if the heat treatment was performed in the presence of only one of the gases, ammonia or hydrogen, or in ammonia + nitrogen. This indicates that the sintering in the temperature range 483 to 523 K only occurs with reduced nickel particles in ammonia + hydrogen. The prevailing mechanism for the sintering seems to be sintering by particle migration. The kinetics of the sintering process indicates that the rate constant is correlated to more factors than the temperature.

Chemisorption

Nickel

Ammonia

Hydrogen

Sintering

Catalyst deactivation

Alumina

Författare

Johan Lif

Chalmers, Kemi- och bioteknik, Teknisk ytkemi

Kompetenscentrum katalys (KCK)

Magnus Skoglundh

Chalmers, Kemi- och bioteknik, Teknisk ytkemi

Kompetenscentrum katalys (KCK)

Lars Löwendahl

Chalmers, Institutionen för material- och ytkemi, Teknisk ytkemi, Keramteknologi

Applied Catalysis A: General

0926-860X (ISSN) 1873-3875 (eISSN)

Vol. 228 1-2 145-154

Drivkrafter

Hållbar utveckling

Styrkeområden

Nanovetenskap och nanoteknik

Energi

Materialvetenskap

Ämneskategorier

Kemiteknik

Kemi

DOI

10.1016/S0926-860X(01)00957-7

Mer information

Skapat

2017-10-07