Hydrogenation of Citral over Ni and Ni-Sn Catalysts

Authors : Hilal AYKAÇ, Selahattin YILMAZ

Pages : 623-635

View : 11 | Download : 6

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :Liquid phase citral hydrogenation over zeolite-supported monometallic Ni and bimetallic Ni-Sn catalysts was studied. The zeolite support materials were Na-Y, Na-mordenite, and clinoptilolite. Ni and Sn contents of the monometallic and bimetallic catalysts were 8.1-9.2 wt% and 0.46 wt%, respectively. The type of the zeolite support affected the activity and selectivity of the catalysts differently. The main product of the citral hydrogenation reaction was citronellal, for both monometallic insert ignore into journalissuearticles values(84.5% yield); and bimetallic insert ignore into journalissuearticles values(44.5% yield); catalysts. The addition of promoter increased the selectivity to unsaturated alcohols insert ignore into journalissuearticles values(geraniol+nerol);, i.e. it changed from 0.9% to 6.3% over mordenite and from 0.9% to 2.1% over Na-Y-supported catalysts. Furthermore, activity of the Ni catalysts decreased while the quantity of acetal remained almost constant. Intimate contact between active metal, promoter, and support, and a catalyst with a high concentration of weak acid sites gave high selectivity to geraniol+nerol.
Keywords : Citral, hydrogenation, citronellol, Ni, Ni Sn, zeolite