Magneli phase titanium sub-oxide conductive ceramic TinO2n-1 as support for electrocatalyst toward oxygen reduction reaction with high activity and stability
来源期刊：中南大学学报(英文版)2015年第4期
论文作者：WU Qiu-mei RUAN Jian-ming ZHOU Zhong-cheng SANG Shang-bin
文章页码：1212 - 1219
Key words：magneli phase TinO2n-1; support; oxygen reduction reaction; stability
Abstract: Magneli phase titanium sub-oxide conductive ceramic TinO2n-1 was used as the support for Pt due to its excellent resistance to electrochemical oxidation, and Pt/TinO2n-1 composites were prepared by the impregnation-reduction method. The electrochemical stability of TinO2n-1 was investigated and the results show almost no change in the redox region after oxidation for 20 h at 1.2 V (vs NHE) in 0.5 mol/L H2SO4 aqueous solution. The catalytic activity and stability of the Pt/TinO2n-1 toward the oxygen reduction reaction (ORR) in 0.5 mol/L H2SO4 solution were investigated through the accelerated aging tests (AAT), and the morphology of the catalysts before and after the AAT was observed by transmission electron microscopy. At the potential of 0.55 V (vs SCE), the specific kinetic current density of the ORR on the Pt/TinO2n-1 is about 1.5 times that of the Pt/C. The LSV curves for the Pt/C shift negatively obviously with the half-wave potential shifting about 0.02 V after 8000 cycles AAT, while no obvious change takes place for the LSV curves for the Pt/TinO2n-1. The Pt particles supported on the carbon aggregate obviously, while the morphology of the Pt supported on TinO2n-1 remains almost unchanged, which contributes to the electrochemical surface area loss of Pt/C being about 2 times that of the Pt/TinO2n-1. The superior catalytic stability of Pt/TinO2n-1 toward the ORR could be attributed to the excellent stability of the TinO2n-1 and the electronic interaction between the metals and the support.
WU Qiu-mei(伍秋美)1, RUAN Jian-ming(阮建明)1, ZHOU Zhong-cheng(周忠诚)1, SANG Shang-bin(桑商斌)2
(1. State Key Laboratory of Powder Metallurgy (Central South University), Changsha 410083, China;
2. School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China)
Abstract:Magneli phase titanium sub-oxide conductive ceramic TinO2n-1 was used as the support for Pt due to its excellent resistance to electrochemical oxidation, and Pt/TinO2n-1 composites were prepared by the impregnation-reduction method. The electrochemical stability of TinO2n-1 was investigated and the results show almost no change in the redox region after oxidation for 20 h at 1.2 V (vs NHE) in 0.5 mol/L H2SO4 aqueous solution. The catalytic activity and stability of the Pt/TinO2n-1 toward the oxygen reduction reaction (ORR) in 0.5 mol/L H2SO4 solution were investigated through the accelerated aging tests (AAT), and the morphology of the catalysts before and after the AAT was observed by transmission electron microscopy. At the potential of 0.55 V (vs SCE), the specific kinetic current density of the ORR on the Pt/TinO2n-1 is about 1.5 times that of the Pt/C. The LSV curves for the Pt/C shift negatively obviously with the half-wave potential shifting about 0.02 V after 8000 cycles AAT, while no obvious change takes place for the LSV curves for the Pt/TinO2n-1. The Pt particles supported on the carbon aggregate obviously, while the morphology of the Pt supported on TinO2n-1 remains almost unchanged, which contributes to the electrochemical surface area loss of Pt/C being about 2 times that of the Pt/TinO2n-1. The superior catalytic stability of Pt/TinO2n-1 toward the ORR could be attributed to the excellent stability of the TinO2n-1 and the electronic interaction between the metals and the support.
Key words:magneli phase TinO2n-1; support; oxygen reduction reaction; stability
