某些C_2－醇、醛和羧酸在Pt／Sb_（ad）电极上电催化氧化研究

Electrocatalytic Oxidation of Some C 2 Compounds(Alcohols, Aldehydes, and Carboxylic acids) on a Pt/Sb ad Electrode

用电位扫描法和旋转电极法等研究了同液和异液ＵＰＤ法制备的Ｐｔ／Ｓｂａｄ电极对某些Ｃ２－醇、醛和羧酸的催化氧化作用，证明该电极对醛基的氧化有显著的催化活性，对羟基氧化的活性很小，对羧基氧化没有活性．跟异液ＵＰＤ法所制Ｐｔ／Ｓｂａｄ电极相比，同液ＵＰＤ法所制电极的活性较小．讨论了Ｐｔ／Ｓｂａｄ电极催化氧化作用的局限性，认为它只能对低电位范围内受毒物抑制的电极反应产生催化效应．通过实验确定了Ｃ２－醛类催化氧化反应的决定速度步骤是醛分子在电极表面的转化步骤，而氧化产物则是草酸。

The electrocatalytic oxidation behavior of some C 2 compounds(alcohols, aldehydes and carboxylic acids) on a Pt/Sb ad electrode prepared in situ or ex situ UPD was investigated using pontential sweep and rotating disc electrode methods. It is confirmed that Pt/Sb ad electrode show the most electrocatalytical active to the oxidation of aldehyde functional group and only a little activity to the oxidation of hydroxyl group, but no activity for the oxidation of carboxyl group. The experimental results show that the activity of the Pt/Sb ad electrode prepared by ex situ UPD is higher than that prepared by in situ UPD. The limitations of the electrocatalytic action of the Pt/Sb ad electrode are discussed. It is believed that the electrode shows activity only to the electrode reactions which are inhibited by the poisons intermediates formed in the low potential region. It is indicated by experiments that the surface transformation of the aldehyde molecules is the rate determing step of the electrocatalytic oxidation of the C 2 aldehydes and the product of the oxidation is oxalic acid. According to that a reation mechanism for the oxidation is proposed.