氮掺杂炭锚定二氧化钛的制备及电催化氧还原性能

Preparation of nitrogen-doped carbon anchoring titanium dioxide and its electrocatalytic oxygen reduction performance

目前人们正在积极寻找非贵金属催化剂以取代昂贵的铂系氧还原反应催化剂。本文研究一种非贵金属催化剂TiO_(2)分散在N掺杂碳(TiO_(2)/N—C)上,其在碱性溶液中的ORR活性与20%(wt)Pt/C相当,其中,在0.1 mol/L KOH溶液中,TiO_(2)/N-C表现出0.96 VRHE的起始电位和0.80 VRHE的半波电位;密度泛函理论计算表明,电子从还原的TiO_(2)转移到N-C可以大大增强石墨化N掺杂剂附近的ORR活性;TiO_(2)/N-C在反应条件下也表现出良好的稳定性和对甲醇的耐受性。这为合理设计廉价高活性ORR催化剂提供了一种新方法。

Currently,people are actively looking for non-precious metal catalysts to replace expensive platinum-based oxygen reduction catalysts.In this study,we report a non-noble metal catalyst,TiO_(2)dispersed on N-doped carbon(TiO_(2)/N-C),which have excellent ORR activity comparable to that of the 20 wt%Pt/C in alkaline solution.Specifically,TiO_(2)/N-C exhibit onset potential of 0.96 VRHE and half-wave potential of 0.80 VRHE in 0.1 M KOH solution.Density functional theory calculations show that electron transfer from the reduced TiO_(2)to the N-C can greatly enhance the ORR activity near the graphitic N dopant.Moreover,TiO_(2)/N-C also displayed great stability under reaction conditions and resistance to methanol poisoning.This provides a new method for the rational design of inexpensive and highly active ORR catalysts.