气溶胶法制备纳米Ni@SiO_(2)及其对肉桂醛催化加氢的研究

Aerosol synthesis of nano Ni@SiO_(2)and its catalytic hydrogenation of cinnamaldehyde

通过气溶胶方法喷雾热解制备出了具有“火龙果型”结构的Ni@SiO_(2)纳米颗粒催化剂。载体硅球与金属纳米颗粒的单分散性良好。通过X射线衍射、透射电子显微镜、氮气物理吸附仪等表征手段对样品进行检测。可以得到平均比表面积约340m^(2)/g,平均孔径约3.4nm,平均孔容约0.16cm^(3)/g的Ni@SiO_(2)催化剂颗粒。其中载体二氧化硅球粒径分布于50~500nm,金属Ni颗粒粒径分布于2~6nm。作为催化剂进行肉桂醛催化加氢实验,以气相色谱作为检测方式,当溶剂为异丙醇,温度为160℃,氢气压力为2MPa,反应时间为2 h时,所得肉桂醛转化率为98.5%,苯丙醛收率为76.8%。

A Ni@SiO_(2)nanoparticle catalyst with a"pitaya"structure was prepared by aerosol spray pyrolysis.The carrier silicon spheres and metal nanoparticles have good monodispersity.The samples were characterized by X-ray diffraction,transmission electron microscopy,nitrogen physical adsorption and other methods.The obtained Ni@SiO_(2)catalyst particles have an average specific surface area of about 340 m^(2)/g,an average pore size of about 3.4 nm,and an average pore volume of about 0.16 cm^(3)/g.The particle size of the carrier silica spheres is distributed between 50-500 nm,and that of Ni particles is between 2-6 nm.Ni@SiO_(2)was used as the catalyst for catalytic hydrogenation of cinnamaldehyde,and gas chromatography was used as the detection method.Under the conditions where the solvent was isopropanol,temperature was 160℃,hydrogen pressure was 2 MPa,and reaction time was 2 hours,the cinnamaldehyde conversion rate obtained was 98.5%,and the phenylpropionaldehyde yield was 76.8%.