Infrared spectrum analysis to the behavior of CO poison on fuel cell

• Main Authors: yuan-chung chen, 陳彥仲
• Other Authors: Sheng-Diann Lin
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/23948517002889018628

碩士 === 元智大學 === 化學工程研究所 === 89 === Abstract An in-situ IR cell was designed to analyze the CO adsorption over catalytic electrode under fuel cells operating conditions. This anodic half-cell chamber was proved to have consistency during electrochemistry and IR spectrum measurements. The IR measurements showed the Pt/C anode became saturated with CO in very short time under low concentration of CO. It’s found that the CO adsorption strength on anode was much weaker when the electrode was moistened, and when the electrode temperature was increased to 80C. Furthermore, CV (Cyclic Voltametry) spectrum demonstrated that adsorbed CO reduced the Hydrogen uptake on Pt/C (and PtRu/C) anode. CO adsorption experiments were performed under controlled potential, in order to analyze the effect of surface H on CO adsorption. It showed that CO could easily break Pt-H bonds to form Pt-CO adsorbent. However, IR data showed that CO adsorption strength was stronger when the electrode surface is free from H. During the following anodic potential scan, the CO adsorption strength was found to even stronger. The surface CO presented up to 1.5V(vs. RHE), without any CO2 formed. However, CO2 formation and the appearance of an oxidation current ranging from 0.85 to 1.25 V (vs. RHE) were found when the anode was subjected to continuous 1% CO/He. This suggests that weakly adsorbed CO is responsible for such CO electro-oxidation under our test conditions.