Rapid Screening of Multi-component Electrocatalysts for Hydrogen Oxidation by Scanning Electrochemical Microscopy

• Main Authors: Cheng-tse Hsieh, 謝承澤
• Other Authors: Yu-ching Weng
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/72201032565246612014

碩士 === 逢甲大學 === 化學工程學所 === 97 === In this research, multi-component electrocatalysts arranged in high-density arrays were prepared on glassy carbon using a piezo- micro dispenser based on the concept of the combinatorial method. The optimal electrocatalyst for hydrogen oxidation reaction (HOR) was rapidly determined using scanning electrochemical microscopy (SECM) in a tip generation–substrate collection (TG-SC) mode. Approach curve and tip/substrate voltammetry (TSV) measurements were used to examine the kinetics of the electrocatalysts toward hydrogen oxidation. Furthermore, the surface morphology and composition of the electrocatalysts were characterized using scanning electron microscope (SEM) and energy dispersive spectrometer (EDS), respectively. All kinds of lead materials were screened with a TG-SC mode. For bimetallic catalysts: Both Pt4Pd6 and Pt6Ir4 alloys possessed better electroactivity toward HOR than Pt catalyst whether in the acid and alkaline solutions. The PtxRuy alloys had good electroactivity in alkaline solutions. For trimetallic catalysts: The Pt2Pd2Ru1 and Pt3Pd1Ru1 alloys showed better electroactivity than the Pt catalyst. Kinetic data were obtained by fitting approach curve on Pt (Tafel slope = 117.65 mV, k0 = 0.41 cm/s, α = 0.50) and Pt4Pd6 catalysts (Tafel slope = 123.46 mV, k0 = 0.51 cm/s, α = 0.52). These catalysts obey the Heyrovsky-Volmer mechanism for ideal reversible HOR. The electroactivity of the catalysts in different applied potential could be observed by TSV analysis.