Crystallization design of MnO2 via acid towards better oxygen reduction activity

被引：36

作者：

Zhang, Bentian ^{[1
]}

Cheng, Gao ^{[1
]}

Lan, Bang ^{[1
,2
]}

Zheng, Xiaoying ^{[1
]}

Sun, Ming ^{[1
]}

Ye, Fei ^{[1
]}

Yu, Lin ^{[1
]}

Cheng, Xiaoling ^{[1
]}

机构：

[1] Guangdong Univ Technol, Key Lab Clean Chem Technol Guangdong Regular High, Sch Chem Engn & Light Ind, Guangzhou 510006, Guangdong, Peoples R China

[2] GuangDong MeiZhou Qual & Metrol Supervis & Testin, Meizhou 514072, Peoples R China

来源：

CRYSTENGCOMM | 2016年 / 18卷 / 36期

基金：

中国国家自然科学基金;

关键词：

ELECTROCATALYTIC ACTIVITY; MANGANESE OXIDES; CATALYTIC-ACTIVITY; WATER OXIDATION; NANOSTRUCTURES; EVOLUTION; DECOMPOSITION; ALPHA-MNO2; MECHANISM; EFFICIENT;

D O I：

10.1039/c6ce01131d

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Manganese dioxide is one of the important electrode materials used for oxygen reduction reaction (ORR) in fuel-cell and metal-air batteries, and its electrochemical activity is greatly influenced by its crystalline structure. To elucidate the crystalline structure effect on the ORR, herein, we designed a facile method to obtain alpha-MnO2 and gamma-MnO2 via adjusting the acid under hydrothermal conditions using the same starting materials and reagents. The prepared alpha-MnO2 and gamma-MnO2 have a similar morphology composed of 3D microscopic spheres made up of numerous nanorods. X-ray photoelectron spectroscopy, temperature programmed desorption of oxygen characterization and conductivity measurements demonstrate that the alpha-MnO2 material has a relatively higher ratio of surface oxygen species, higher oxygen mobility and higher electrical conductivity. When compared with gamma-MnO2, alpha-MnO2 displays superior ORR activity with a higher electron transfer number and lower yield of peroxide species in alkaline solutions. The obtained results shed new light on the crystalline structure-dependent ORR activity of MnO2.

引用

页码：6895 / 6902

页数：8