Effect of Sintering Temperature on Adhesion Property and Electrochemical Activity of Pt/YSZ Electrode

Jixin Wang; Jiandong Cui; Xiao Zhang; Wentao Tang; Changhui Mao

doi:10.3390/ma15103471

Effect of Sintering Temperature on Adhesion Property and Electrochemical Activity of Pt/YSZ Electrode

Materials (Basel). 2022 May 12;15(10):3471. doi: 10.3390/ma15103471.

Authors

Jixin Wang^{1

2

3}, Jiandong Cui^{1

2

3}, Xiao Zhang^{1

2}, Wentao Tang^{1

2

3}, Changhui Mao^{1

2

3}

Affiliations

¹ GRINMAT State Key Laboratory of Advanced Materials for Smart Sensing, GRINM Group Co., Ltd., Beijing 100088, China.
² GRIMAT Engineering Institute Co., Ltd., Beijing 101407, China.
³ General Research Institute for Nonferrous Metals, Beijing 100088, China.

Abstract

The (Pt/YSZ)/YSZ sensor unit is the basic component of the NO_x sensor, which can detect the emission of nitrogen oxides in exhaust fumes and optimize the fuel combustion process. In this work, the effect of sintering temperature on adhesion property and electrochemical activity of Pt/YSZ electrode was investigated. Pt/YSZ electrodes were prepared at different sintering temperatures. The microstructure of the Pt/YSZ electrodes, as well as the interface between Pt/YSZ electrode and YSZ electrolyte, were observed by SEM. Chronoamperometry, linear scan voltammetry, and AC impedance were tested by the electrochemical workstation. The results show that increasing the sintering temperature (≤1500 °C) helped to improve adhesion property and electrochemical activity of the Pt/YSZ electrode, which benefited from the formation of the porous structure of the Pt/YSZ electrode. For the (Pt/YSZ) electrode/YSZ electrolyte system, O^2- in YSZ is converted into chemisorbed O₂ on Pt/YSZ, which is desorbed into the gas phase in the form of molecular oxygen; this process could be the rate-controlling step of the anodic reaction. Increasing the sintering temperature (≤1500 °C) could reduce the reaction activation energy of the Pt/YSZ electrode. The activation energy reaches the minimum value (1.02 eV) when the sintering temperature is 1500 °C.

Keywords: NOx sensor; Pt/YSZ electrode; electrochemical activity; electrochemical analysis; sintering temperature.

Grants and funding

This research was funded by the Shandong Province Key R&D Program (No.2020CXGC010203). And The APC were funded by the Shandong Province Key R&D Program(No.2020CXGC010203) and Technology Innovation Fund of GRIMAT (Grant No. 57272101).