Electrocatalytic “Volcano-Type” Effect of Nano-TiO₂ (A)/(R) Phase Content in Pt/TiO₂-CN_x Catalyst

Authors

Ai-Lin Cui, Institute of Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, 100083, China;
Yang Bai, Institute of Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, 100083, China;
Hong-Ying Yu, Institute of Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, 100083, China;
Hui-Min Meng, Institute of Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, 100083, China;Follow

Corresponding Author

Hui-Min Meng(menghm16@126.com)

Abstract

The relationship between the electrochemical activity of fuel cell catalysts and Pt particle size, as well as the catalyst support and co-catalyst is still unclear. In this work, FESEM, XRD, BET, TEM and CV techniques were adopted to investigate the effects of TiO₂ anatase (A)/rutile (R) phases content on the electrochemical activity of Pt electrocatalyst. The results showed that the anatase-rutile phase transformation occurred during the heat treatment of TiO₂ at 700 ~ 900 ^oC accompanied by the growth of two-phase crystalline size, and anatase was completely transformed into rutile at 900 ^oC. TEM results revealed that the ultrafine Pt electrocatalysts with the particle size of 1.8 ~ 2.8 nm were successfully prepared over the TiO₂-CN_x supports. The content of TiO₂ (A)/(R) phases had a “volcano-type” effect on both the BET surface area of TiO₂-CN_x supports and the real “effective” electrochemical active surface area (ECSA) of Pt/TiO₂-CN_x catalysts. When the rutile content was 25%, the TiO₂(25%R)-CN_x support and Pt/TiO₂(25%R)-CN_x catalyst had the largest specific surface area and the most electrochemical active sites, respectively. It is speculated that raising the rutile content, there might be a strong metal-support interaction between Pt nanoparticles and TiO₂(25%R)-CN_x support with the rutile content of 25%, which could anchor the ultrafine Pt nanoparticles, resulting in the highest ECSA of Pt/TiO₂(25%R)-CN_x catalyst. Therefore, the Pt/TiO₂(25%R)-CN_x became more suitable as a catalyst for fuel cells.

Graphical Abstract

Keywords

catalyst, TiO2, anatase, rutile, electrochemical active surface area

DOI Link

https://doi.org/10.13208/j.electrochem.211002

Publication Date

2022-05-28

Online Available Date

2022-01-02

Revised Date

2021-12-21

Received Date

2021-12-15

Recommended Citation

Ai-Lin Cui, Yang Bai, Hong-Ying Yu, Hui-Min Meng. Electrocatalytic “Volcano-Type” Effect of Nano-TiO₂ (A)/(R) Phase Content in Pt/TiO₂-CN_x Catalyst[J]. Journal of Electrochemistry, 2022 , 28(5): 2110021.
DOI: 10.13208/j.electrochem.211002
Available at: https://jelectrochem.xmu.edu.cn/journal/vol28/iss5/3