Preparation of PdCoIr Tetrahedron Nanocatalysts and Its Performance toward Ethanol Oxidation Reaction

Authors

Zhi-Yuan Yu, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;
Rui Huang, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;Follow
Jie Liu, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;
Guang Li, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;
Qian-Tong Song, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;
Shi-Gang Sun, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;Follow

Corresponding Author

Rui Huang(rhuang@xmu.edu.cn);
Shi-Gang Sun(sgsun@xmu.edu.cn)

Abstract

As a new energy conversion device, direct ethanol fuel cells (DEFCs) are widely concerned because of their remarkable advantages such as high theoretical energy density and wide fuel sources. However, the rapid development of DEFCs has been severely impeded due to the sluggish kinetic process and toxic intermediates especially in their anodic reactions. Palladium (Pd)-based materials are considered to be excellent anode catalysts for DEFCs, especially under alkaline conditions. And further improving their performance is an important direction to promote the development of DEFCs. Surface structure and composition are the key factors affecting the performance of catalysts which can be improved by reasonable regulation. It is reported that high-index faceted structures and element doping are beneficial to improve the performance of catalyst. In this work, the advantages of these two strategies were used comprehensively to prepare Pd-based catalysts with high efficiency. Palladium cobalt (PdCo) and Ir-doped PdCo tetrahedron alloy nanocatalysts (denoted by PdCo-TH and PdCoIr-TH, respectively) have been successfully prepared by one-step hydrothermal method. The characterization results of TEM, ICP, XPS and CV show that the PdCo-TH binary and PdCoIr-TH ternary alloys were formed, while Ir element was mainly distributed on the PdCoIr-TH surface. Compared with the commercial Pd/C, the PdCo-TH/C and PdCoIr-TH/C exhibited the enhanced catalytic properties toward ethanol oxidation reaction in alkaline solutions. Particularly, the Pd₉Co₁Ir_0.1-TH/C catalyst showed the best activity and stability toward EOR, especially at low potentials (< -0.25 V). And Ir sites not only resisted CO poison effectively, but also shifted the initial oxidation potential of ethanol negatively. Meanwhile, the selectivity of C1 products during the electrocatalytic oxidation of ethanol has been greatly improved with the increase of Ir content. The enhanced reactivities of PdCo-TH/C and PdCoIr-TH/C could be attributed to: (a) The coexistence of Co sites and Ir sites on the surfaces can generate OH_ad species which can promote the oxidation of intermediate adsorbed species on Pd sites and (b) the negative shift in electron binding energy of Pd due to the addition of Ir may make reaction intermediates desorb more difficultly, which might make the reactivity of PdCoIr-TH/C differ from that of PdCo-TH/C. This research work has demostrated a strategic approach for future development in high efficiency catalysts used for DEFCs.

Graphical Abstract

Keywords

tetrahedron alloy nanocatalysts, PdCoIr, PdCo, ethanol oxidation reaction, electrocatalysis

DOI Link

https://doi.org/10.13208/j.electrochem.200515

Publication Date

2021-02-28

Online Available Date

2020-06-10

Revised Date

2020-06-09

Received Date

2020-05-15

Recommended Citation

Zhi-Yuan Yu, Rui Huang, Jie Liu, Guang Li, Qian-Tong Song, Shi-Gang Sun. Preparation of PdCoIr Tetrahedron Nanocatalysts and Its Performance toward Ethanol Oxidation Reaction[J]. Journal of Electrochemistry, 2021 , 27(1): 63-75.
DOI: 10.13208/j.electrochem.200515
Available at: https://jelectrochem.xmu.edu.cn/journal/vol27/iss1/10