MICROWAVE-ASSISTED COMBUSTION SYNTHESIS OF CHROMIUM NITRIDE IN A FLUIDIZED BED

摘要

Combustion synthesis experiments have been conducted in a fluidized bed, using nitrogen as the flui-dizing gas, for the formation of transition-metal nitrides. These nitrides can be potential replacements for traditional hydrodenitrogenation and hydrodesulfurization catalysts that are currently used in hydrocarbon fuel processing. To augment the production of the catalysts, microwave-assisted ignition and propagation of reaction in the fluidized bed has been investigated for its potential to produce nanolayers of the nitride on chromium particle substrates. Nanolayers have been shown in other investigations to enhance catalytic activity. The results indicate that microwave assistance results in controlled formation of nanometer chromium nitride overlayers. The composition of the overlayers have been inferentially confirmed by using a variety of characterization techniques: x-ray diffraction, scanning electron microscopy combined with energy dispersive spectroscopy, and transmission electron microscopy.