Preparation Of Nano-Ni/SiO 2 Catalyzed Hydrogenation Of α-pinene By Adsorption Phase Reaction

Pinane was important intermediates of terpenic fragrance such as geraniol,linalool,musk rose and dihydrogen bay enol,which were widely used in the spice production.Pinane existed two kinds of isomers（cis and trans）,the activity of tran-s-pinane was much less than the cis-pinane,so cis-pinane was required priority on the industrial production.α-pinene was prepared by pinene catalytichydrogenat-ion,and there were lots of α-pinene in turpentine.Turpentine oil resources was extremely rich in our country.There fore,the preparation of cis-pinane from cataly-zing α-pinene hydrogenation had very important significance.Nano Ni was a kind of particles which grain size in 1 nm to 100 nm,it had magnetism,conducti-ve thermal conductivity and other properties,were widely used in industry.The nanometer particle which was prepared by adsorption phase reaction technology,its size was small,dispersivity was good,so the adsorption phase reaction technol-ogy was used to prepare supported nano Ni catalyst and the catalyst was used to catalyze α-pinene hydrogenation reaction.The following several aspects of rese arch were done:（1）Through an experiment,the adsorption phase reaction technique was use-d to prepare the supported Ni/SiO₂ nanometer catalyst for hydrogenation,TEM,SEM,XRD,TG-DSC was used to characterize catalyst.The result showed that the catalyst had good catalytic performance;the active components were better load-ed on the carrier surface;particle well dispersed,particle size was smaller;had Good thermal stability.（2）The supported Ni/SiO₂ nanometer catalyst prepared by adsorption phase reaction technique was used for hydrogenation,gas chromatography was used to analyze hydrogenated products,to investigate the catalytic activity of the catalyst.Its preparation conditions were studied,the suitable preparation conditions were obtained:2ml water adsorption,the ratio of Ni/SiO₂ was 1:3,theformation of adsor-ption phase temperature was 35℃,adsorption temperature was 35 ℃,reduction temperature was75℃,the capacity was 0.5.（3）Though single factor and orthogonal experiment to investigate the reacti-on condition of turpentine oil hydrogenation catalyzed by the supported Ni/SiO₂ nanometer catalyst,the suitable process conditions were got:reaction pressure was 4MPa,the reaction temperature was 140℃,reaction time was 2.5h,catalyst dosage was 10%.Under the conditions.the a-pinene conversion rate was 98.91%,the cis-pinane selectivity was 81.0%.The investigation experiment-s of catalyst life show-ed that the catalyst were continuously used 3 times.the conversion of a-pinene was still above 90%,the selectivity of cis-pinane could reach more than 80%.The adsorption phase reaction technology was used to prepare supported Ni/SiO₂ catalyst to catalyze a-pinene hydrogenation.In this paper,with cheap Ni as active component,instead of the expensive precious metal catalyst,the catalytic effect and stability were better.