Pt/Co-N-C电催化材料的制备及其碱性ORR性能  

Preparation of Pt/Co-N-C Electrocatalytic Material and Its ORR Performances in Alkaline Electrolyte

作　　者：任志立 段磊 徐守冬[1] 陈良[2] 易群 张鼎 REN Zhili;DUAN Lei;XU Shoudong;CHEN Liang;YI Qun;ZHANG Ding(College of Chemical Engineering and Technology,Taiyuan University of Technology,Taiyuan 030024,China;College of Chemistry,Taiyuan University of Technology,Taiyuan 030024,China;School of Chemical Engineering and Pharmacy,Wuhan Institute of Technology,Wuhan 430205,China)

机构地区：[1]太原理工大学化学工程与技术学院,太原030024 [2]太原理工大学化学学院,太原030024 [3]武汉工程大学化工与制药学院,武汉430205

出　　处：《人工晶体学报》2023年第4期654-662,共9页Journal of Synthetic Crystals

基　　金：国家自然科学基金(21978193,21606158,21706171);山西省回国留学人员科研资助项目(2022-049)。

摘　　要：金属有机框架材料(MOFs)是一种制备过渡金属-氮-碳(M-N-C)氧还原电催化材料的有效前驱体,但在热解过程中结构坍塌等问题限制了其实际应用。本研究通过表面活性剂F-127包覆以及Zn掺杂对ZIF-67进行改性,并对改性后的Zn-ZIF-67@F-127在氩气气氛下进行热解,制得结构完整的Co-N-C载体。通过在Co-N-C载体表面进行Pt的负载,制备了Pt/Co-N-C复合氧还原反应(ORR)催化剂,并对其在碱性电解液中的ORR催化性能进行了探究。实验结果表明,F-127的加入提高了Zn-ZIF-67@F-127在热解过程中的形貌保持率,Pt/Co-N-C在O2饱和的0.1 mol·L^(-1)KOH中,催化剂的起始电位、半波电位、极限扩散电流密度分别为1.027 V、0.836 V和5.51 mA·cm^(-2),与商用20%Pt/C性能相近。Pt与Co-N-C的协同作用使得催化剂不仅对ORR的四电子路径显示出高选择性,更在计时电流测试中表现出接近于商用20%Pt/C的稳定性与较商用20%Pt/C更优的抗甲醇性能。Metal-organic frameworks(MOFs)are regarded as effective precursors for the preparation of M-N-C oxygen reduction electrocatalytic materials.However,the structural collapse of MOFs during the pyrolysis limits their practical application.In this study,ZIF-67 was firstly modified by coating with the surfactant of F-127 and doping with Zn.After that,the modified Zn-ZIF-67@F-127 was pyrolyzed under argon atmosphere to fabricate the Co-N-C support with complete structure.By loading Pt on the surface of Co-N-C support,the Pt/Co-N-C composite catalyst for oxygen reduction reaction(ORR)was obtained.The ORR catalytic performances in the alkaline electrolyte were systematically studied.The experimental results show that the addition of F-127 can improve the morphological retention of Zn-ZIF-67@F-127 during the pyrolysis.More importantly,the onset potential,half-wave potential,and diffusion-limited current density of Pt/Co-N-C in O2-saturated 0.1 mol·L^(-1) KOH are 1.027 V,0.836 V,and 5.51 mA·cm^(-2),respectively,which are similar to those of the commercial 20%Pt/C catalyst.The synergistic effect of Pt and Co-N-C not only exhibits a high selectivity and current density for the ORR four-electron pathway,but also shows a high stability approaching the commercial 20%Pt/C catalyst,and superior methanol resistance performance compared with the commercial 20%Pt/C in the chronoamperometry test.

关 键 词：Pt/Co-N-C电催化材料 氧还原反应 ZIF-67 F-127 碱性电解液 抗甲醇性能 

分 类 号：O643.36[理学—物理化学]