Ni-Fe-Al-O双金属催化剂在生物质基2-羟基四氢吡喃还原胺化合成5-氨基-1-戊醇中的性能研究北大核心CSCD

采用共沉淀法制备了不同Fe/Ni摩尔比(0、0.125、0.25、0.5和0.75)的Al_(2)O_(3)负载型NiFe单、双金属催化剂,并考察了它们在生物糠醛衍生2-羟基四氢吡喃(2-HTHP)还原胺化合成高附加值5-氨基戊醇反应中的催化性能.研究发现当Fe/Ni摩尔比为0.25时表现出最高的5-氨基戊醇收率(在80℃和2 MPa优化条件下达90%).利用N_(2)吸脱附、X射线衍射(XRD)、氢气程序升温还原(H_(2)-TPR)、透射电镜(TEM)等技术对催化剂进行了表征,结果表明适量Fe的掺入可以提高催化剂的分散性和还原性,同时在还原活化催化剂中形成Ni-Fe合金相,继而使相应催化剂表现出更优异的催化活性.通过固定床对比考察了催化剂的稳定性,NiFe(0.25)-Al-O双金属催化剂表现出明显优于NiFe(0)-Al-O单金属催化剂的稳定性,运行120 h前者只有微弱失活而后者显著失活.对比反应后催化剂表征发现,金属Fe的修饰可以有效抑制金属活性颗粒的烧结和流失,从而显著提高其反应稳定性.

Reductive Amination of Biomass-Derived 2-Hydroxytetrahydropyran to 5-Amino-1-Pentanol over Bimetallic Ni-Fe/Al2O3 Catalysts

Al2O3 supported NiFe bimetallic catalysts with different Fe/Ni molar ratios (0, 0.125, 0.25, 0.5 and 0.75) were prepared by co-precipitation method for the reductive amination (RA) of biofurfural-derived 2-hydroxytetrahydropyran (2-HTHP) to synthesis valuable 5-amino-1-pentanol (5-AP) and best catalytic performance was obtained when the Fe/Ni mole ratio is 0.25. The effect of metal Fe modification on the catalyst structure, in combination with the evaluation of the catalytic activity and stability was studied in 2-HTHP reductive amination. The results show that incorporation of appropriated Fe could improve the dispersity and reducibility of the catalyst. Moreover, the formation of Ni-Fe alloy structure showed better catalytic activity and stability on bimetallic catalyst. Through the XRD and TEM analysis of the used catalyst showed that the Ni-Fe alloy structure could effectively inhibit the sintering and leaching of active metal particles, thus significantly improving its stability.