Influence of Preparation Modes on Pt-Ni/CNTs Catalysts Used in the Selective Hydrogenation of Cinnamaldehyde to Hydrocinnamaldehyde

摘要

Pt-Ni/CNTs catalysts are prepared by different impregnation techniques and different reduction methods(H2,HCHO,and KBH4)for the selective hydrogenation of cinnamaldehyde(CMA)to hydrocinnamaldehyde(HCMA)and investigated by transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS),and temperature programmed reduction(H2-TPR)techniques.The results show that the catalytic selectivity and activity of the Pt-Ni/CNTs catalysts would significantly be improved by using KBH4 as a reducing agent,due to the electronic synergetic effect of Pt-Ni-B,and 96% for conversion of CMA and 88% for selectivity of HCMA are obtained over Pt-Ni/CNTs catalyst reduced by KBH4.Furthermore,the hydrogenation rate of CMA and selectivity of CMA to HCMA over Pt-Ni/CNTs catalyst are significantly improved in the presence of trace base or acid promoters again.The best result(92% for conversion of CMA and 96% for selectivity of HCMA)is obtained when NaOAc is used as base promoter.