The effect of precipitants on Ni-Al(2)O(3) catalysts prepared by a co-precipitation method for internal reforming in molten carbonate fuel cells
Ni-Al(2)O(3) catalysts are prepared via the co-precipitation method using various precipitants: urea, Na(2)CO(3), NaOH, K(2)CO(3), KOH and NH(4)OH. The effects of the precipitants on the physicochemical properties and catalytic activities of the Ni-Al(2)O(3) catalysts are investigated. The Ni50-urea catalyst displays the largest specific surface area and the highest pore volume. This catalyst also exhibits the highest Ni dispersion and the largest Ni surface area. Ni50-urea catalyst prepared with urea as precipitant and Ni50-K(2)CO(3) catalyst prepared with K(2)CO(3) as precipitant exhibit high pore volumes and good catalytic activities for methane steam reforming. The Ni50-urea catalyst exhibits the best physicochemical properties and shows good catalytic activity and a strong resistance to electrolyte contamination.
Hydrogenation of quinoline by ruthenium nanoparticles immobilized on poly(4-vinylpyridine)
A series of catalysts composed of ruthenium nanoparticles immobilized on poly(4-vinylpyridine) was prepared by NaBH(4) reduction of RuCl(3).3H(2)O in methanol in the presence of the polymer; TEM measurements of a 10 wt % Ru/P4VPy material indicate that ruthenium particles of 1-2 nm predominate. This catalyst is efficient for the selective hydrogenation of quinoline to 1,2,3,4-tetrahydroquinoline at 100-120 ºC and 30-40 bar H(2). The activity increases with hydrogen pressure up to 40 bar but is essentially independent of quinoline concentration. Polar solvents, triethylamine, and acetic acid enhance catalytic performance, suggesting an ionic mechanism involving heterolytic hydrogen activation.
Catalytic inactivation of SARS coronavirus, and yeast on solid surface
Catalytic oxidation is a potential way to disinfect air through a air-condition system. We find that the SARS coronavirus, bacteria and yeast are completely inactivated in 5 min on Ag catalyst surface and in 20 min on Cu catalyst surface at room temperature in air. Scanning electron microscopy (SEM) images show that the yeast cells are dramatically destructed on the Ag/AlO and Cu/AlO surfaces, which indicates that the inactivation is caused by catalytic oxidation rather than by toxicity of heavy metals.