光还原法合成Pt/Fe_(2)O_(3)/氮掺杂还原氧化石墨烯催化剂及其抗烧结性能  

Synthesis and Sintering Resistance of Pt/Fe_(2)O_(3)/N Doped Reduced Graphene Oxide Catalysts by Photo⁃Reduction Method

作　　者：李志慧 王云鹏 符婉琳 朱明芸 柴蕴玲 吴敏[1] 孙岳明[1] 代云茜[1] LI Zhi-Hui;WANG Yun-Peng;FU Wan-Lin;ZHU Ming-Yun;CHAI Yun-Ling;WU Min;SUN Yue-Ming;DAI Yun-Qian(School of Chemistry and Chemical Engineering,Southeast University,Nanjing 211189,China)

机构地区：[1]东南大学化学化工学院,南京211189

出　　处：《无机化学学报》2022年第1期73-83,共11页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金(No.21975042);江苏省六大人才高峰基金(No.XCL⁃082);江苏省军民融合创新平台(No.6907041203);东南大学新进全职博士后科研启动费(No.1107040239)资助。

摘　　要：采用静电纺丝法获得的多孔Fe_(2)O_(3)纳米棒与氮掺杂还原氧化石墨烯(N⁃RGO)的复合材料作为载体,通过光还原法成功制备清洁、高活性的Pt/Fe_(2)O_(3)/N⁃RGO催化剂,并进一步研究其中的光还原反应机理和催化剂的抗烧结性能。研究结果表明,在可见光照射下,Fe_(2)O_(3)对光的强吸收作用促使光生电子和空穴的产生,N⁃RGO有效延长光生载流子的寿命,使得电子从O^(2-)转移到Fe^(3+)。Fe_(2)O_(3)/N⁃RGO中部分还原的Fe^(2+)具有较强的还原能力,可使PtCl_(6)^(2-)在Fe_(2)O_(3)表面还原并迅速成核,生长为粒径约2.13 nm的Pt纳米颗粒。此外,甲醇作为空穴清除剂可以快速有效地消耗掉扩散到载体表面的光生空穴,使导带中积累的电子与PtCl_(6)^(2-)发生还原反应,从而提高Pt纳米颗粒的光还原速率。电纺Fe_(2)O_(3)纳米棒独特的粗糙表面为Pt纳米颗粒异相成核提供了大量活性位点。富含点缺陷的N⁃RGO片层能缩短Fe_(2)O_(3)的光生载流子扩散路径,提高光沉积的效率;同时,其特征褶皱结构可以作为物理屏障,防止Pt纳米颗粒聚集。得益于金属与载体间的强相互作用,在500℃高温老化后,Pt纳米颗粒仍能维持较小的尺寸(2.67 nm),表现出优良的抗烧结性能。在对硝基苯酚加氢反应中,Pt/Fe_(2)O_(3)/N⁃RGO在400℃老化后仍具有高达22.2 L·g^(-1)·s^(-1)的反应速率常数,约为老化前的1.6倍。Porous Fe_(2)O_(3) nanorods and nitrogen⁃doped reduced graphene oxide(N⁃RGO)composite materials obtained by electrospinning were used as the carrier to successfully prepare clean and highly active Pt/Fe_(2)O_(3)/N⁃RGO catalyst by photoreduction method.The synthesis mechanism of the photoreduction reaction and the sintering resistance of the catalyst were further studied.During visible light irradiation,the efficient light absorption of Fe_(2)O_(3) facilities the generation of photoelectrons and holes,while N⁃RGO highly prolongs the lifetime of photogenerated carriers.In this case,partially reduced Fe^(2+)in Pt/Fe_(2)O_(3)/N⁃RGO has a strong reduction ability,which can make PtCl_(6)^(2-)reduce on the surface of Fe_(2)O_(3) and nucleate rapidly,and grow into Pt nanoparticles with a diameter of about 2.13 nm.Methanol as a hole scavenger can effectively and quickly consume the photo⁃generated holes on the surface of the carrier,which causes the electrons accumulated in the conduction band to undergo a reduction reaction with PtCl_(6)^(2-),and greatly accelerates the formation rate of Pt nanoparticles.Fe_(2)O_(3) nanorods with ultra⁃high porosity provide numerous nucle⁃ation sites for Pt nanoparticles.N⁃RGO sheets with abundant defects can shorten the diffusion path of Fe_(2)O_(3) photo⁃carriers and improve the efficiency of Pt photo⁃deposition.Besides,its characteristic wrinkle structure can act as a physical barrier to prevent Pt nanoparticles from agglomeration.Due to the strong interaction between metal and car⁃rier,the size of Pt nanoparticles remained at 2.67 nm even after aging at 500℃.Pt/Fe_(2)O_(3)/N⁃RGO catalyst still had excellent thermal stability and catalytic activity after aging at 400℃,with a reaction rate constant of up to 22.2 L·g^(-1)·s^(-1),which was about 1.6 times of that before aging.

关 键 词：静电纺丝 光沉积 Fe_(2)O_(3) PT 还原氧化石墨烯 

分 类 号：O614.811[理学—无机化学] O614.826[理学—化学]