Modest Oxygen-Defective Amorphous Manganese-Based Nanoparticle Mullite with Superior Overall Electrocatalytic Performance for Oxygen Reduction Reaction

Chao Dong; Zi-Wei Liu; Jie-Yu Liu; Wei-Chao Wang; Lan Cui; Rui-Chun Luo; Hui-Long Guo; Xue-Li Zheng; Shi-Zhang Qiao; Xi-Wen Du; Jing Yang

doi:10.1002/smll.201603903

Modest Oxygen-Defective Amorphous Manganese-Based Nanoparticle Mullite with Superior Overall Electrocatalytic Performance for Oxygen Reduction Reaction

Small. 2017 Apr;13(16). doi: 10.1002/smll.201603903. Epub 2017 Feb 13.

Authors

Chao Dong¹, Zi-Wei Liu¹, Jie-Yu Liu², Wei-Chao Wang², Lan Cui¹, Rui-Chun Luo³, Hui-Long Guo⁴, Xue-Li Zheng¹, Shi-Zhang Qiao^{1

5}, Xi-Wen Du¹, Jing Yang¹

Affiliations

¹ Institute of New-Energy Materials, Key Laboratory of Advanced Ceramics and Machining Technology of Ministry of Education, School of Materials Science and Engineering, Tianjin University, Tianjin, 300072, China.
² College of Electronic Information and Optical Engineering, Nankai University, Tianjin, 300071, China.
³ Frontier Research Center for Materials Structure, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
⁴ Institute of Advance Polymer Materials, School of Materials Science and Engineering, Tianjin University, Tianjin, 300072, China.
⁵ School of Chemical Engineering, The University of Adelaide, Adelaide, SA, 5005, Australia.

PMID: 28195444
DOI: 10.1002/smll.201603903

Abstract

Manganese-based oxides have exhibited high promise as noncoinage alternatives to Pt/C for catalyzing oxygen reduction reaction (ORR) in basic solution and a mix of Mn^3+/4+ valence is believed to be vital in achieving optimum ORR performance. Here, it is proposed that, distinct from the most studied perovskites and spinels, Mn-based mullites with equivalent molar ratio of Mn³⁺ and Mn⁴⁺ provide a unique platform to maximize the role of Mn valence in facile ORR kinetics by introducing modest content of oxygen deficiency, which is also beneficial to enhanced catalytic activity. Accordingly, amorphous mullite SmMn₂ O_5-_δ nanoparticles with finely tuned concentration of oxygen vacancies are synthesized via a versatile top-down approach and the modest oxygen-defective sample with an Mn³⁺ /Mn⁴⁺ ratio of 1.78, i.e., Mn valence of 3.36 gives rise to a superior overall ORR activity among the highest reported for the family of Mn-based oxides, comparable to that of Pt/C. Altogether, this study opens up great opportunities for mullite-based catalysts to be a cost-effective alternative to Pt/C in diverse electrochemical energy storage and conversion systems.

Keywords: amorphous; mullites; oxygen reduction reactions; oxygen vacancies; specific activities.

Publication types

Research Support, Non-U.S. Gov't