The Preparation And Research Of Electrode For Catalyzing Organic Small Molecules

Direct alcohols fuel cell (DAFC) has been intensively researched and developed in recent years. It is significant to study on electro-catalysis of micromolecule alcohols, not only of fundamental research but practical application. It is necessary to develop new catalysts with high performance for electrooxidation of micromolecule alcohols.Polyaniline, one kind of conducting polymers, with porous structure and high surface area, is usually used as matrix to incorporate matel particles possessing catalytic activity, such as Pt, Sn, to prepare X-modified polyaniline electrodes, X-PANi/Pt (X=Pt, PtSn). It is proved that X-PANi/Pt has a high efficiency in electrooxidation of small molecules such as methanol, ethanol and formic acid. In this paper, studies on oxidation phenomena of methanol on PtSn-PANi/Pt electrode, ethanol on Pt-PANi/Pt electrode, and effect of preparing process on electrocatalytic properties, were carried out. Effect of electrochemical parameters on electrocatalytic properties of PANi/Pt electrode prepared with pulsating potential method (PPM) was investigated using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and scanning electron microcopy (SEM). The results of SEM indicated that the mesh structural PANi films prepared with PPM were provided with splendid mechanical character and high specific surface area, appropriate to be the matrix to load activators.PtSn-PANi/Pt electrodes were prepared with pulsating potential method and constant potential method respectively. The results of CV and EIS showed that the PtSn-PANi/Pt electrode possessed higher higher catalytic activity to methanol, as Sn improved antitoxic stability of the eletrode and prolong service life of the eletrode. And Effect of the load radio of Pt and Sn on electrocatalytic properties of PtSn-PANi/Pt electrode was also researched.Pt-modified PANi film electrode was prepared by PPM and electrooxidation of ethanol on PtSn-PANi/Pt electrode was investigated. The rusult was received that PANi had no catalytic activity on ethanol by comparing the curves of cyclic voltammetry tests of PANi/Pt and Pt-PANi/Pt electrode in the acid solution. Effect of load of Pt, temperature of reaction and deposition method on catalytic activity on ethanol was studied. Three characteristic peaks emerged in the curves of cyclic voltammetry when ethanol electrooxidized in the acid solution. When the temperature was 40℃, Pt-PANi/Pt electrode possessed high catalytic activity. The deposition method of Pt affected the catalytic activity of electrode distinctly.