以硝酸镍为镍源、酸/碱性硅溶胶为硅源,采用共沉淀法制备了 2种Ni/SiO2催化剂.采用固定床反应器,评价Ni/SiO2催化剂对于2-甲基呋喃(2-MF)气相加氢合成2-甲基四氢呋喃(2-MTHF)的反应性能.通过XRD、N2等温吸附-脱附、H2-TPR、NH3-TPD、XPS、FTIR和TEM对催化剂进行了表征.考察了硅溶胶的酸碱性对Ni/SiO2催化剂结构及性能的影响.结果表明,以酸性硅溶胶为硅源制备的Ni/SiO2催化剂以弱酸中心酸量为主且存在中强酸中心,比表面积、平均孔径大,因而该催化剂加氢活性和2-MTHF的选择性较高.Ni/SiO2催化剂稳定性良好,在最优反应条件[温度90 ℃、H2压力2 MPa、质量空速4.4 g 2-MF/(g催化剂·h)、H2与2-MF物质的量之比为4∶1]下进行催化剂稳定性测试(200 h),2-MF的转化率达到99.8％,2-MTHF的选择性均保持在97.5％左右.
Catalytic performance of Ni/SiO2 for 2-methylfuran hydrogenation
Ni/SiO2 catalyst was prepared from coprecipitation of nickel nitrate and acid/alkaline silica sol,haracterized by XRD,N2 isothermal adsorption and desorption,hydrogen temperature-programmed reduction(H2-TPR),temperature-programmed desorption of ammonia(NH3-TPD),XPS,FTIR and TEM,and evaluated for its catalytic performance for 2-methylfuran(2-MF)gas phase hydrogenation to 2-methyltetrahydrofuran(2-MTHF)in a fixed bed reactor.The effect of acidity and alkalinity of silica sol on the structure and performance of the catalyst was also investigated.The results showed that the Ni/SiO2 catalyst prepared with acidic silica sol possessed more amount of weak acid sites and medium strong acid sites,larger specific surface area and average pore size,which was beneficial for the improvement of catalyst activity and 2-MTHF selectivity.Moreover,Ni/SiO2 catalyst exhibited good stability.Under the conditions of reaction temperature 90 ℃,hydrogen pressure 2 MPa,mass hourly space velocity 4.4 g 2-MF/(gcat·h),molar ratio value of H2 to 2-MF of 4∶1 and reaction time 200 h,the conversion of 2-MF reached 99.8％,and the selectivity of 2-MTHF remained about 97.5％.
2-methyltetrahydrofuran2-methylfuranco-precipitation methodNi/SiO2acidity and alkalinitycatalysis technology
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