甲酸在Pt(100)单晶电极表面解离吸附过程的动力学

A DYNAMIC INVESTIGATION OF THE DISSOCIATIVE ADSORPTION OF HCOOH ON Pt (100) SINGLE CRYSTAL ELECTRODE

有机小分子在电催化剂表面的解离吸附,是燃料电池阳极氧化过程中发生自毒化现象的主要原因.事实上这类解离吸附是一种表面分子过程,包括有机分子在电极表面吸附,分子内断键,生成新的吸附分子或基因等步骤.Sun等研究了甲醇等在一系列铂单晶电极上的解离吸附,发现这类过程极强地依赖于电极表面原子排列结构.虽然已有大量文献报导了运用原位红外光谱检测各类有机小分子解离吸附物种,但迄今仍未见到动力学方面的研究结果.显然,对这种在电化学条件下表面分子反应过程的动力学研究。

Dissociative adsorption of small organic molecules on electrocatalyst is an impor-tant molecular process of surface, which includes stages of adsorption, chemical bondbroken and new adsorbate formation. The dynamic study on this reaction will contri-bute to reveal the origin of interaction between electrode surface and reactants, andto develop and enrich theories of electrocatalysis. In the present work, in situ FTIRstudies demonstrated that the dissociative products of HCOOH on Pt electrode areCO_(ad) species. The oxidation of CO_(ad) formed from HCOOH dissociative adsorption onPt(100) electrode was used as probe reaction, and the dynamic properties of thisdissociative adsorption were investigated by a computerized experimental set-updeveloped recently in our group. From the analysis of current transients the rate ofdissociative adsorption of HCOOH on Pt(100) electrode has been evaluated underspecified conditions.