铂电极上锑吸附原子对1,2-丙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1,2 丙二醇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,Sb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剥离部份Sb可方便地得到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,可显著提高1,2 丙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1,2 丙二醇氧化的峰电流增加了近2倍.作者还从表面质量变化提供了吸附原子电催化作用的新数据.

Adsorption of Sb on Pt Electrodes and Effect on Oxidation of 1, 2-Propanediol

The electrochemical behaviors of irreversibly adsorbed antimony on Pt electrode and the processes of adsorption and oxidation of 1,2-propanediol on Pt/Sb_(ad) electrodes were studied by using cyclic voltammetry and electrochemical quartz crystal microbalance (EQCM). The results demonstrated that the Sb adatoms are stable on Pt electrode when the electrode potentials are below 0.50V(SCE) and the saturation coverage of Sb_(ad) is 0.34. It proved that various coverages of Sb_(ad) can be easily 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 1,2-propanediol oxidation. In contrast to Pt electrodes, the oxidation peak current of 1,2-propanediol in this case twice increased. The EQCM studies provided quantitative results of surface mass variation during 1,2-propanediol oxidation, and have thrown new light on elucidating effects of adatom Sb_(ad) on Pt electrode surface towards 1, 2-propanediol oxidation.