The relationship between the kind of carriers used for nickel catalysts and the yield of N-ethylpiperidine has been investigated in the hydrogenation of pyridine with nickel catalysts in ethanol. A nickel catalyst with alumina as the carrier has been found particularly excellent, and a very high yield of N-ethylpiperidine was obtained when the reaction was performed at 185200°C under 4565 kg/cm
2 of hydrogen pressure. Nickel-alumina catalysts containing small quantities of magnesia, zinc oxide, or calcium oxide also gave excellent results. One of the reasons for the good results with the alumina-supported catalysts has been assumed to be ther superior activities for the dehydrogenation of ethanol which is considered to be the rate-determiming step for the formation of N-ethylpiperidine.
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