离子液体调控合成Pt-Pd双金属纳米材料及其催化氨硼烷水解释氢  

Ionic Liquid-Modulated Synthesis of Pt-Pd Bimetallic Nanomaterials and Their Catalytic Performance for Ammonia Borane Hydrolysis to Generate Hydrogen

作　　者：李慧慧 姚开胜[1] 赵亚南 范李娜 田钰琳 卢伟伟[1] LI Hui-Hui;YAO Kai-Sheng;ZHAO Ya-Nan;FAN Li-Na;TIAN Yu-Lin;LU Wei-Wei(Chemical Engineering&Pharmaceutics School,Henan University of Science&Technology,Luoyang 471023,China)

机构地区：[1]河南科技大学化工与制药学院,洛阳471023

出　　处：《应用化学》2023年第4期597-609,共13页Chinese Journal of Applied Chemistry

基　　金：国家自然科学基金(No.21673067);河南省科技攻关项目(No.192102210043)资助。

摘　　要：在离子液体溴化1-十四烷基-3-甲基咪唑([C14mim]Br)的调控下,以聚乙烯吡咯烷酮(PVP)为稳定剂,在90℃水溶液中一步制备出双金属Pt-Pd纳米材料。通过透射电子显微镜(TEM)、扫描电子显微镜(SEM)、高角度环形暗场扫描透射电镜(HAADF-STEM)、X射线能谱(EDS)、X射线衍射仪(XRD)和X射线光电子能谱(XPS)等对产物的形貌、结构、组成和价态等进行了详细的表征分析。结果表明,除了纯Pd样品,其它比例的Pt-Pd纳米材料均具有多孔结构。离子液体对多孔Pt-Pd纳米材料的调控起到了重要作用,对于[Cnmim]Br离子液体,当烷基侧链长≥C12时,有利于形成多孔的Pd@Pt核壳球形结构。在氨硼烷水解释氢实验中,不同比例的Pt-Pd双金属纳米材料均表现出优于商用Pd/C的催化活性。其中,Pt3Pd7纳米材料具有最优的催化性能,催化过程在6 min内完成,产氢率高达100%。氨硼烷水解释氢的活化能(Ea)为36.15 kJ/mol,周转频率(TOF)为35.72 mol/(mol·min)。循环5次反应仅需51 min,产率仍能达到100%,表明该催化剂具有较高的催化活性和稳定性。Herein,under the modulation of an ionic liquid 1-tetradecyl-3-methylimidazole bromide([C14mim]Br),Pt-Pd bimetallic nanomaterials are prepared in one-pot at 90℃in aqueous solution with polyvinylpyrrolidone(PVP)as the stabilizer.The morphology,structure,components and valence states of the products are characterized and analyzed in detail by transmission electron microscopy(TEM),scanning electron microscopy(SEM),high-angle annular dark-field scanning transmission electron microscopy(HAADFSTEM),energy dispersive X-ray spectroscopy(EDS),X-ray diffractometry(XRD)and X-ray photoelectron spectrometer(XPS).The results show that except for pure Pd sample,Pt-Pd bimetallic nanomaterials with other Pt/Pd ratios have porous structures.[C14mim]Br plays an important role in regulating the synthesis of Pt-Pd porous nanomaterials.For the ionic liquids[Cnmim]Br with the alkyl chain length≥C12,it is beneficial for the formation of porous Pd@Pt spherical structures.In the experiment of the ammonia borane hydrolysis,Pt-Pd bimetallic nanomaterials with various ratios show higher catalytic activities than commercial Pd/C,among which Pt3Pd7 nanomaterials have the best catalytic performance.The hydrogen generation reaction can be quickly achieved within only 6 min and the hydrogen yield is up to 100%.At 25℃,the activation energy(Ea)and the turnover frequency(TOF)values are calculated to be 36.15 kJ/mol and 35.72 mol/(mol·min),respectively.Furthermore,the reaction for the five catalytic cycles can be achieved within 51 min,and the yield can still reach 100%,indicating that the catalyst has high activity and good stability.

关 键 词：离子液体 Pt-Pd双金属 纳米材料 氨硼烷水解释氢 

分 类 号：O643.3[理学—物理化学]