In situ transmission difference FTIR spectroscopic investigation on anodic oxidation of methanol in aqueous solution

In situ transmission difference FTIR spectroscopy method was introduced for studying the anodic oxidation of methanol in acid aqueous solution. A minigrid Pt optically transparent thin layer electrode was used as working electrode. This method has the ability to clarify the identity of species involved in the oxidation process both in solution and adsorbed at the surface of electrode. From the results of in situ transmission difference FTIR spectroscopy measurement it was found that HCHO, HCOOH, HCOOCH₃ and CH₂(OCH₃)₂ could be formed in the oxidation process of methanol. The final product was CO₂. The adsorbed poisonous intermediate CO was detected. It was formed at near 0.6 V and became significant at 0.9 V, where the oxidation current was inhibited. The in situ transmission difference FTIR spectroscopy method is a very convenient, relative simplicity and efficient method for investigating the electrochemical process, and could be as a good candidate for further application.