Measurement of the state of metal dispersion on supported nickel catalysts by gas chemisorption

摘要: Gas chemisorption has been investigated as a technique for the estimation of state nickel dispersion on supported hydrocarbon conversion catalysts. Published studies catalysts are critically reviewed. Catalysts which were examined included alumina and zeolites. measurements supplemented by X-ray diffraction line-broadening determinations to establish average crystallite sizes. Nickel areas estimated from hydrogen at 250°C vapor pressure 100 mm mercury size determined in good agreement. These results provide strong evidence that dissociative adsorption occurs only crystallites sufficient offer adjacent sites. Carbon monoxide room temperature carbon mercury, after correction support, provides more accurate measure total area including an atomic dispersion. A combination or measurement, plus chemisorption, can be used estimate relative amounts comparatively large (∼50 A) essentially dispersion, well specific surface these two ranges.