Sintering of nickel particles supported on gamma-alumina in ammonia
Journal article, 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

Author

Johan Lif

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Competence Centre for Catalysis (KCK)

Magnus Skoglundh

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Competence Centre for Catalysis (KCK)

Lars Löwendahl

Chalmers, Department of Materials and Surface Chemistry, Applied Surface Chemistry, Ceramic Technology

Applied Catalysis A: General

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

Vol. 228 1-2 145-154

Driving Forces

Sustainable development

Areas of Advance

Nanoscience and Nanotechnology (2010-2017)

Energy

Materials Science

Subject Categories

Chemical Engineering

Chemical Sciences

DOI

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

More information

Created

10/7/2017