不同载体镍基催化剂对1,4-丁炔二醇加氢性能的影响

Effect of different carriers on performance of nickel-based catalysts in hydrogenation of 1,4-butynediol

采用等体积浸渍法将Ni分别负载在USY、ZSM-5、SBA-15、Al_(2)O_(3)和SiO_(2)5种载体上制备Ni质量分数为17%的负载型镍基催化剂,以1,4-丁炔二醇(BYD)加氢制1,4-丁二醇(BDO)为探针反应考察其催化性能。通过X射线衍射、N_(2)吸附-脱附、H_(2)程序升温还原及NH_(3)程序升温脱附对催化剂进行表征。结果表明,在不同载体的催化剂作用下,BYD的转化率均可达到99%以上,但BDO的选择性却有很大差异;其他条件相同时,Ni/SBA-15催化剂反应5 h时BDO的选择性达到83.1%,1,4-丁烯二醇(BED)的选择性为16.6%,且2-羟基四氢呋喃(HTHF)的选择性很低,这与Ni/SBA-15具有较大的比表面积和平均孔径、较弱的酸性和良好的活性金属组分镍分散性有关。进而筛选出在低温低压条件下BYD一步加氢制备BDO的镍基催化剂Ni/SBA-15。

Ni-based catalysts with a Ni mass fraction of 17%are prepared on USY,ZSM-5,SBA-15,Al_(2)O_(3)and SiO_(2)carriers,respectively through the equal volume impregnation method.Their catalytic performance is evaluated through the hydrogenation of 1,4-butynediol(BYD)to 1,4-butanediol(BDO).The catalysts are characterized by means of XRD,N_(2)adsorption-desorption,H_(2)-TPR and NH_(3)-TPD.The results indicates that the conversion of BYD can exceed 99%over the catalysts with different carriers,but the selectivity of BDO varies greatly according to different carries.The selectivity of BDO reaches 83.1%,that of 1,4-butenediol is 16.6%,and that of 2-hydroxytetrahydrofuran is very low when Ni/SBA-15 catalyst is served,the reaction has performed for 5 h while other conditions remain the same.This can be attributed to Ni/SBA-15's large specific surface area,high average pore size,and weak acidity as well as good dispersion of nickel.Ni/SBA-15 is screened for one-step hydrogenation of BYD to prepare BDO under low temperature and low pressure conditions.