含氧空位TiO_(2)-CNT负载Pt单原子电催化剂的电化学性能  

Electrochemical performance of oxygen-containing vacancy TiO_(2)-CNT support Pt single-atom electrocatalyst

作　　者：王肖博 闫岸如[2] 朱玲 兰天[2] 刘学胜[2] 马淑芳 王智勇 WANG Xiaobo;YAN Anru;ZHU Ling;LAN Tian;LIU Xuesheng;MA Shufang;WANG Zhiyong(School of Materials Science&Engineering,Shaanxi University of Science&Technology,Xi'an 710021,Shaanxi,China;School of Physics and Optoelectronic Engineering,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]陕西科技大学材料科学与工程学院,陕西西安710021 [2]北京工业大学物理与光电工程学院,北京100124

出　　处：《精细化工》2024年第12期2710-2716,共7页Fine Chemicals

基　　金：JKW重点项目(EW101003202202)。

摘　　要：为降低Pt负载型催化剂的Pt负载量和原子利用率,以羧基化多壁碳纳米管(MWCNT)和钛酸四丁酯为原料,通过溶胶-凝胶法制备了TiO_(2)-CNT复合载体,采用高温热处理在其表面引入大量氧空位(O_(V))缺陷,最后通过沉积沉淀法使Pt单原子(Pt SA)负载在TiO_(2)(O_(V))-CNT上,制备了一种含氧空位缺陷的复合载体锚定Pt SA的电催化剂Pt SA/TiO_(2)(O_(V))-CNT。采用XRD、电子顺磁共振波谱仪(EPR)、HAADF-STEM、XPS对Pt SA/TiO_(2)(O_(V))-CNT进行了表征,采用标准的三口电解池对其电化学性能进行了评价。结果表明,TiO_(2)-CNT上成功引入了氧空位缺陷,并将Pt SA锚定在TiO_(2)(O_(V))-CNT晶格中,Pt SA和TiO_(2)(O_(V))-CNT之间存在电荷转移,形成了共价配位键,具有金属载体强相互作用。Pt SA/TiO_(2)(O_(V))-CNT的半波电位为0.804 V,0.90 V时的质量活性(MA)451.24 A/g(Pt),Tafel斜率63.75 m V/dec,在10000 s的氧还原(ORR)运行过程中,归一化电流下降17%,展现了较优的ORR动力学。Pt SA/TiO_(2)(O_(V))-CNT以较低的Pt负载量(质量分数1.13%)表现出较高的催化活性,得益于氧空位对Pt SA的强锚定作用和TiO_(2)薄膜对CNT的保护作用。In order to reduce the Pt loading and atom utilization of Pt-supported catalysts,TiO_(2)-CNT composite support was prepared from carboxylated multi-walled carbon nanotubes(MWCNT)and tetrabutyl titanate via sol-gel method,and its surface was introduced a large number of oxygen vacancy(O_(V))defects by high temperature heat treatment.An electrocatalyst Pt SA/TiO_(2)(O_(V))-CNT anchored by a composite support with oxygen vacancy defects was then prepared by deposition-precipitation of Pt single-atom(Pt SA)on TiO_(2)(O_(V))-CNT,characterized by XRD,electron paramagnetic resonance spectroscopy(EPR),HAADF-STEM and XPS,and evaluated by standard three-port electrolytic cell for its electrochemical performance.The results showed that oxygen vacancy defects were successfully introduced onto TiO_(2)-CNT and Pt SA was anchered in the TiO_(2)(O_(V))-CNT lattice,with charge transfer between the two forming strong metal-support interactions.Pt SA/TiO_(2)(O_(V))-CNT exhibited a half-wave potential of 0.804 V,a mass activity(MA)of 451.24 A/g(Pt),and a Tafel slope of 63.75 m V/dec at 0.90 V.During oxygen reduction(ORR)operation for 10000 s,the normalized current decreased by 17%,showing better ORR dynamics.Pt SA/TiO_(2)(O_(V))-CNT showed high catalytic activity with lower Pt loading(mass fraction 1.13%),due to the strong anchoring effect of oxygen vacancy on Pt SA and the protective effect of TiO_(2)film on CNT.

关 键 词：氧空位 复合载体 单原子 半波电位 质量活度 原子利用率 

分 类 号：TM911.42[电气工程—电力电子与电力传动] TQ426[化学工程]