Study of the electrochemical oxidation mechanism of formaldehyde on gold electrode in alkaline solution

The oxidation of formaldehyde in alkaline solution was studied by in situ rapid-scan time-resolved IR spectroelectrochemistry（RS-TR-FTIRS） method.In the potential range between -0.7 V and 0.2 V,the gem-diol anions were oxidized(according to the 2765 cm;of-ν;and 1034 cm;ofν;downward IR bands) and the formate ions appeared(according to the 1588,1357 cm;of the asymmetric and symmetricν;and 1380 cm;ofδ;upward IR bands) in aqueous solution.It was also confirmed that gem-diol anion was oxidized(according to the 2026,1034 cm;downward IR bands) to formate ions (according to the 1595,1357,1380 cm;upward IR bands) and water(according to the 3427 cm;ofν;upward IR band) in heavy water solution.The results illustrated that formaldehyde formed gem-diol anion in alkaline solution and was absorbed on the electrode surface;then gem-diol anion was oxidized to formate ions and water.