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采用焙烧法制备γ-Fe2O3之后,再利用3-氨丙基三乙氧基硅烷(APTES)对其表面进行功能化修饰,在其溶液体系中加入氯铂酸/氯化钯溶液,使游离的四价铂粒子/二价的钯离子吸附在磁性纳米粒子表面,与氨基化基团形成配位化合物,在超声化学作用下,利用水合肼将铂离子和钯离子还原为单质,制成γ-Fe2O3/M(M=Pt/Pd)复合磁敏催化剂纳米粒子。并采用Bruker Advanced-D8粉末衍射仪,带有选区电子衍射(SAED)的透射电子显微镜(TEM),高分辨透射电子显微镜(HRTEM)和带有超导量子干涉装置(SQUID)功能的磁性测量系统(MPMS)等对γ-Fe2O3粒子和γ-Fe2O3/M复合粒子磁性进行表征。结果表明:采用焙烧法制备的γ-Fe2O3磁性纳米粒子粒径在20 nm左右,制备的γ-Fe2O3/Pt和γ-Fe2O3/Pd复合粒子粒径分别在68和36 nm左右,室温下的磁化强度分别为29.4和31.2(A·m2)/kg,磁响应性能优越,可用于磁敏催化剂反应体系。这为贵金属Pt、Pd催化剂的回收与磁敏催化剂应用提供了新的思路。
After the preparation of γ-Fe2O3 by calcination method, the surface was functionalized with 3-aminopropyltriethoxysilane (APTES), and chloroplatinic acid / palladium chloride solution was added to the solution system to make free Tetravalent platinum particles / divalent palladium ions are adsorbed on the surface of the magnetic nanoparticles to form coordination compounds with the aminated groups, and the platinum ions and palladium ions are reduced to the simple substance by the hydrazine hydrate under the action of the ultrasonic chemical reaction to obtain γ- Fe2O3 / M (M = Pt / Pd) Composite Magnetic Sensitive Catalyst Nanoparticles. A Bruker Advanced-D8 powder diffractometer, transmission electron microscopy (TEM) with selected area electron diffraction (SAED), high resolution transmission electron microscopy (HRTEM) and magnetic measurement system with superconducting quantum interference device (SQUID) (MPMS) were used to characterize the magnetic properties of γ-Fe2O3 particles and γ-Fe2O3 / M composite particles. The results show that the particle size of γ-Fe2O3 magnetic nanoparticles prepared by calcination is about 20 nm, and the particle sizes of γ-Fe2O3 / Pt and γ-Fe2O3 / Pd composite particles are about 68 and 36 nm respectively. The magnetization The intensities are 29.4 and 31.2 (A · m2) / kg, respectively. The magnetic response is superior and can be used in the magnetosensitive catalyst reaction system. This provides a new way for the recovery of noble metal Pt and Pd catalysts and the application of magnetosensitive catalysts.