Electrochemical Preparations and Applications of Nano-Catalysts with High-Index Facets

Authors

Chi XIAO, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry,College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;
Na TIAN, 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
Zhi-you ZHOU, 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;

Corresponding Author

Na TIAN(tnsd@xmu.edu.cn)

Abstract

The performance of catalysts highly depends on their surface structure and composition. Nanocrystals bounded by high-index facets usually exhibit high catalytic activity due to their high-density low-coordinated step atoms with high reactivity. In this paper, we have reviewed the preparations of noble metals (e.g., Pt, Pd and Rh) nanocatalysts with high-index facets by electrochemical square-wave potential method developed in our group. The square-wave potential method includes a nucleation procedure to generate nuclei, followed by a square-wave potential procedure for a certain period of time for the growth of nuclei into nanocrystals. The formation mechanism of high-index facets is also discussed. The surface structure was determined by the combined effect of nanocrystals growing at the lower potential and etching at the higher potential, as well as the rearrangement effect by the repetitive adsorption/desorption of oxygen species induced by the square-wave potential. By tuning the upper or lower square-wave potential, the evolution of Pt nanocrystals can be controlled from tetrahexahedron to hexoctahedron, and then to trapezohedron, or from tetrahexahedron to truncated ditetragonal prism. Considering the importance in utilization of noble metal in practical applications, emphasis is also given to the small-sized Pt tetrahexahedron of high mass-specific activity. By combining seed-mediated method with square-wave potential method, sub-10 nm tetrahexahedral Pt nanocrystals enclosed with {210} high-index facets were synthesized from 3 nm Pt nanoparticles. We have then described the application of electrochemical square-wave potential method for the synthesis of high-index faceted nanocrystals in deep eutectic solvents. Pt concave nanocubes with {hk0} facets, Pt triambic icosahedra with {hhl} facets, Pd concave-disdyakis triacontahedra with {hkl} facets, and concave Au hexoctahedra with {hkl} facets and trisoctahedra with {hhl} facets were synthesized. To further boost the catalytic activity, surface modification of foreign atoms on high-index faceted metal nanocrystals including the modification of Cu on Pd tetrahexahedra to tune the selectivity of electro-reduction of CO₂ is presented. Finally, an outlook of high-index faceted nanocatalysts is given.

Graphical Abstract

Keywords

high-index facet, electrochemical preparation, electrocatalyst, tetrahexahedron, Pt-group metal

DOI Link

https://doi.org/10.13208/j.electrochem.181244

Publication Date

2020-02-28

Online Available Date

2019-04-09

Revised Date

2019-04-09

Received Date

2019-02-19

Recommended Citation

Chi XIAO, Na TIAN, Zhi-you ZHOU, Shi-gang SUN. Electrochemical Preparations and Applications of Nano-Catalysts with High-Index Facets[J]. Journal of Electrochemistry, 2020 , 26(1): 61-72.
DOI: 10.13208/j.electrochem.181244
Available at: https://jelectrochem.xmu.edu.cn/journal/vol26/iss1/8