Trifunctional Single-Atomic Ru Sites Enable Efficient Overall Water Splitting and Oxygen Reduction in Acidic Media

Xianyun Peng; Shunzheng Zhao; Yuying Mi; Lili Han; Xijun Liu; Defeng Qi; Jiaqiang Sun; Yifan Liu; Haihong Bao; Longchao Zhuo; Huolin L Xin; Jun Luo; Xiaoming Sun

doi:10.1002/smll.202002888

Trifunctional Single-Atomic Ru Sites Enable Efficient Overall Water Splitting and Oxygen Reduction in Acidic Media

Small. 2020 Aug;16(33):e2002888. doi: 10.1002/smll.202002888. Epub 2020 Jul 14.

Authors

Xianyun Peng¹, Shunzheng Zhao², Yuying Mi¹, Lili Han³, Xijun Liu¹, Defeng Qi¹, Jiaqiang Sun⁴, Yifan Liu⁵, Haihong Bao¹, Longchao Zhuo⁶, Huolin L Xin³, Jun Luo¹, Xiaoming Sun⁷

Affiliations

¹ Center for Electron Microscopy and Tianjin Key Lab of Advanced Functional Porous Materials, Institute for New Energy Materials and Low-Carbon Technologies, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin, 300384, China.
² Department of Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
³ Department of Physics and Astronomy, University of California, Irvine, CA, 92697, USA.
⁴ State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi, 030001, China.
⁵ Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen, 518060, China.
⁶ School of Materials Science and Engineering, Xi'an University of Technology, Xi'an, 710048, China.
⁷ State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Centre for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.

PMID: 32662944
DOI: 10.1002/smll.202002888

Abstract

Development of cost-effective, active trifunctional catalysts for acidic oxygen reduction (ORR) as well as hydrogen and oxygen evolution reactions (HER and OER, respectively) is highly desirable, albeit challenging. Herein, single-atomic Ru sites anchored onto Ti₃ C₂ T_x MXene nanosheets are first reported to serve as trifunctional electrocatalysts for simultaneously catalyzing acidic HER, OER, and ORR. A half-wave potential of 0.80 V for ORR and small overpotentials of 290 and 70 mV for OER and HER, respectively, at 10 mA cm^-2 are achieved. Hence, a low cell voltage of 1.56 V is required for the acidic overall water splitting. The maximum power density of an H₂ -O₂ fuel cell using the as-prepared catalyst can reach as high as 941 mW cm^-2 . Theoretical calculations reveal that isolated Ru-O₂ sites can effectively optimize the adsorption of reactants/intermediates and lower the energy barriers for the potential-determining steps, thereby accelerating the HER, ORR, and OER kinetics.

Keywords: acidic environment; overall water splitting; oxygen reduction; single-atomic Ru sites; trifunctional catalysts.

Abstract

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