Pt(110)/Sb电极上甲酸的电催化氧化特征和动力学

Kinetics and Characteristics of Electrocatalytic Oxidation of Formic Acid on Pt(110)/Sb Electrodes

研究了 Sb在 Pt( 1 1 0 )晶面上不可逆吸附电化学特性及甲酸在 Sbad修饰 Pt( 1 1 0 )电极 [Pt( 1 1 0 ) /Sb]上的电催化氧化特征及其反应动力学 .发现当扫描电位的上限 Eu≤ 0 .4 5 V时 ,Sbad可稳定地吸附在 Pt( 1 1 0 )表面上 ,从而有效地抑制了甲酸的解离吸附 .与未修饰的 Pt( 1 1 0 )上的结果相比 ,在 Pt( 1 1 0 ) /Sb上甲酸氧化的峰电位负移了 0 .35 V.当θSb=0 .1 2 6时 ,Pt( 1 1 0 ) /Sb电极对甲酸的电催化活性最高 .还研究了 Pt( 1 1 0 ) /Sb上甲酸氧化反应的动力学 ,定量解析了不同θSb下甲酸氧化的速度常数

The electrochemical behavior of irreversibly adsorbed antimony on Pt(110) was studied by using cyclic voltametry. The results demonstrated that the Sb ad atoms are stable on Pt(110) when the electrode potentials are below 0.45 V( vs. SCE). We illustrated that various coverages of Sb ad can be easily obtained by controlling the number of potential cycling and the upper limit of potential scan. It was found that the dissociative adsorption of formic acid was inhibited by the presence of Sb ad on Pt(110) surface. The electrocatalytic effects of Sb ad toward HCOOH electrooxidation is demonstrated by the negative shift of oxidation potential(about 0.35 V) and the enhancement of oxidation current. The maximum current density was measured for a Sb coverage of 0.126. Based on methods developed in our previous papers, the kinetics of HCOOH electrooxidation on Pt(110)/Sb electrodes of different θ Sb has been studied, and both the rate constant k f and transfer coefficient β were determined quantitatively.