ISSN:
1572-896X
Keywords:
nanoparticles
;
surface state
;
reactivity
;
aerosol catalysis
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
,
Technology
Notes:
Abstract Nickel nanoparticles produced by spark discharges were used as aerosol catalyst for the formation of methane. The available surface area of the particles was determined using different methods. It was found that the surface area available for nitrogen adsorption and, therefore, for the methanation reaction remained virtually constant during restructuring of the agglomerates while the surface area based on the mobility was significantly reduced. In general, the reaction parameters such as activation energy and reaction rates agree well with the values for single nickel crystals and foils. At temperatures above 350°C the activation energy and the photoelectric activity of the particles decrease indicating the formation of graphite on the particle surface. Also the change of the work function points to the build up of multiple layers of graphite on the particle surface. The surprisingly low temperature for the surface deactivation may indicate an enhanced formation of carbon atoms at the surface.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1010016919254
