Pt电极上Sb吸附原子对1,3-丁二醇电催化氧化性能的影响

运用电化学循环伏安(CV)和电化学原位石英晶体微天平(EQCM),研究了Pt电极表面不可逆吸附Sb原子的电化学特性以及Pt电极上Sb吸附原子对0.1mol·L-1H2SO4溶液中1,3 丁二醇(1,3 BDL)电催化氧化性能的影响.研究发现,当扫描电位的上限Eu≤0.50V(SCE)时,Sbad可以稳定地吸附在Pt电极表面,饱和覆盖度为0.34;通过控制电位扫描上限和扫描圈数可得到Sbad的不同覆盖度;Pt电极表面Sb吸附原子能在较低的电位下吸附氧,显著提高1,3 丁二醇电催化氧化活性.与Pt电极相比较,Sb饱和吸附原子修饰的Pt电极使1,3 丁二醇氧化的峰电位负移了0.25V,峰电流增加近1倍.该文从表面质量变化提供了吸附原子电催化作用的新证据.

Adsorption and Oxidation of 1,3-Butanediol on Pt and Sb Modified Pt Electrodes Using Cyclic Voltammetry and EQCM

The electrochemical behaviors of irreversibly adsorbed antimony on Pt electrode and the processes of adsorption and oxidation of 1,3-butanediol on Pt, Pt/Sb_(ad) electrodes are studied by using cyclic voltammetry and electrochemical quartz crystal microbalance (EQCM). The results demonstrate that Sb adatoms are stable on Pt electrode when the electrode potentials are below 0.50 V(SCE) and its saturation coverage of Sb_(ad) is 0.34. It has been demonstrated that various coverages of Sb_(ad) can easily be obtained by stripping partially Sb_(ad) starting from a saturation adsorbed Pt/ Sb_(ad) surface. Sb adatoms on Pt surface can adsorb oxygen at relatively low potentials, and exhibit catalytic effects for 1,3-butanediol oxidation. In comparison with the case of Pt electrode, the oxidation peak potential of 1,3-butanediol on Pt surface modified with Sb in saturation is negatively shifted by about 250 mV with peak current doubled. The study of EQCM provides quantitative results of surface mass variation du-ring 1,3-butanediol oxidation, and throws new light in elucidating effects of adatom Sb_(ad) on Pt electrode surface towards 1,3-butanediol oxidation.