酸性介质中1,2-丙二醇在铂电极上吸附和氧化过程的原位FTIR反射光谱研究  

IN-SITU FTIR STUDIES ON ADSORPTION AND OXIDATION OF 1,2-PROPANEDIOL AT A PLATINUM ELECTRODE IN ACID SOLUTIONS

作　　者：孙世刚[1] 杨东方[1] 田昭武[1] 

机构地区：[1]固体表面物理化学国家重点实验室厦门大学化学系,厦门361005

出　　处：《物理化学学报》1992年第1期59-63,共5页Acta Physico-Chimica Sinica

摘　　要：应用电化学循环伏安和原位FTIR反射光谱研究1,2-丙二醇在Pt电极上吸附和氧化过程。结果指出1,2-丙二醇的电氧化可按双途径进行。其一经1,2-丙二醇在Pt上解离吸附产物氧化至CO_2。但在较低电位下这些解离吸附产物(红外检测为CO_(ad)、?C=CH_2]_(ad)等)累积吸附于电极上,毒化Pt表面抑制其它反应。当电位大于0.3V后它们一经生成即氧化脱附,从而使1,2-丙二醇得以在未毒化Pt表面经反应中间体氧化至CO_2。在实验条件下,原位FTIR反射光谱检测到的反应中间体可能有HOC-CHOHCH_3(或CH_2OHCOCH_3)和HOOC-COCH_3(或HOOC-CHOHCH_3)等物种。Adsorption and oxidation of 1,2-propanediol at a platinum electrode in acidsolutions were investigated by cyclic voltammetry and in-situ FTIR spectroscopy.The results demonstrated that 1,2-propanediol oxidized on Pt electrode via a dualpath reaction mechanism.1,2-propanediol may be oxidized into CO_2 through its disso-ciative products on Pt surface. But at lower potentials these dissociative products,which were mainly CO_(ad) and[?C=CH_2]_(ad) as detected by in situ-FTIR spectroscopy,may adsorb strongly and accumulate on electrode, empoisoning Pt electrode andsuppressing consequently other reactions.However all dissociative products may beoxidized and desorbed from Pt surface when E>0.3V, which reactivates Pt electrodeand enables that 1,2-propanediol oxidizes via reactive intermediates into CO_2.Thereactive intermediates were detected by in-situ FTIR spectroscopy under present con-ditions as OHC-CHOHCH_3(or CH_2OH-COCH_3)and HOOC-COCH_3(or HOOC-CHOHCH_3)species.

关 键 词：丙二醇 电氧化 吸附 FTIR反射光谱 

分 类 号：O623.413[理学—有机化学]