Noble metal catalysts catalyze the hydrogenation of pyridine and its derivatives

Supported highly dispersible nanonoble metal catalysts and ruthenium-containing bimetallic catalysts were prepared, and the catalytic performance of the catalysts for the hydrogenation reaction of pyridine and its derivatives was investigated.
The results showed that the catalytic activity of 5% ruthenium carbon catalyst for pyridine hydrogenation reaction was higher than that of 5% palladium carbon and 5% platinum carbon, and the conversion rate of pyridine hydrogenation catalyzed by 5% ruthenium carbon was greater than 99.9%, and the selectivity of piperidine was 100% under the conditions of 100 degrees, 3.0Mpa, 1 hour and ruthenium/pyridine molar ratio of 2.5/1000. After the catalyst was reused for 5 times, the activity and selectivity did not decrease significantly. After adding a small amount of palladium and iridium to the ruthenium carbon catalyst, there was no significant change in the catalyst activity.
X-ray diffraction, high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy were used to characterize the reduced ruthenium-carbon catalyst, and the results showed that ruthenium existed in a highly dispersed metal state, its average particle size was less than 5nm, and the hydrogenation activity of different substrates was: pyridine≈2-methylpyridine>2,6-dimethylpyridine>3-methylpyridine>4-methylpyridine, >3,5-dimethylpyridine>2-methoxypyridine.




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