氮掺杂碳载体促进铂纳米颗粒电催化氧还原反应的作用机制研究  

Study of the mechanism of nitrogen doping in carbon supports on promoting electrocatalytic oxygen reduction reaction over platinum nanoparticles

作　　者：孙雪琴 高新华[3] 王英勇[1] 童希立[1] SUN Xue-qin;GAO Xin-hua;WANG Ying-yong;TONG Xi-li(State Key Laboratory of Coal Conversion,Analytical Instrumentation Center,Institute of Coal Chemistry,Chinese Academy of Sciences,Taiyuan 030001,China;University of Chinese Academy of Sciences,Beijing 100049,China;State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering,Ningxia University,Yinchuan 750021,China)

机构地区：[1]中国科学院山西煤炭化学研究所煤转化国家重点实验室,山西太原030001 [2]中国科学院大学,北京100049 [3]宁夏大学省部共建煤炭高效利用与绿色化工国家重点实验室,宁夏银川750021

出　　处：《燃料化学学报》2022年第11期1427-1436,共10页Journal of Fuel Chemistry and Technology

基　　金：supported by National Natural Science Foundation of China (U1710112);Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering (2022-K71)。

摘　　要：氮掺杂碳通常被用作铂基催化剂电催化氧还原反应的功能载体,但是,掺杂的氮对分子氧在铂活性中心上的吸附和还原机理尚不清楚。本研究采用氨气热解的方法制取氮掺杂纳米碳作为载体,并采用调节氨气热解温度进而控制不同种类氮掺杂的含量,可以使铂催化剂获得较高的零价铂含量、较大的电化学活性面积、合适的铂粒径(2.10 nm)和电子快速传输能力从而提高电催化活性。研究发现,具有最佳氮含量掺杂的Pt/Nano-NC-800催化剂显示出优异的电催化氧还原性能(例如,半波电位为0.80 V vs RHE,极限扩散电流为5.37 mA/cm^(2)),以及强的抗甲醇和一氧化碳中毒能力。该性能优于商业铂碳催化剂(20%,JM)以及大多数沉积在碳纳米颗粒或其他载体上的铂催化剂,表现出优异的应用潜力。Nitrogen-doped carbons(Nano-NC)are often employed as functional supports for boosting oxygen reduction reaction(ORR)over Pt-based catalysts,however,the mechanism of N doping on the adsorption and activation of molecular oxygen on Pt active sites is still not clear.Herein,Nano-NCs as the supports were prepared by a facile NH_(3) antipyretic method,which allowed to tune the kinds of nitrogen species in carbon matrix and their contents by adjusting the NH_(3) antipyretic temperatures.With such an exquisite control,the Pt nanoparticles loaded on the as-obtained Nano-NC showed an optimal Pt particle size(2.10 nm),a higher content of Pt^(0),a large electrochemically active surface area,and fast electron transport ability.As a consequence,the Pt/Nano-NC-800 catalyst with the optimal N-doping showed an outstanding ORR performance with half-wave potential of 0.80 V vs.RHE,limit diffusion current of 5.37 mA/cm^(2) and improved methanol/CO anti-poisoning,which is superior to the commercial Pt/C catalyst(20%,JM),and most of previously reported Pt-based catalysts.This work may pave a way for the design of the advanced supports for Pt-based catalysts for the ORR applications.

关 键 词：氮掺杂碳 纳米颗粒尺寸 氧还原反应 机理 

分 类 号：O643.3[理学—物理化学]