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-dial anions were oxidized (according to the 2765 cm(-1) of v(H-0) and 1034 cm(-1) of v(co) downward IR bands) and the formate ions appeared (according to the 1588, 1357 cm-1 of the asymmetric and symmetric v(oco) and 1380 cm(-1) of delta(C-H) upward IR bands) in aqueous solution. It was also confirmed that gem-diol anion was oxidized (according to the 2026, 1034 cm-1 downward IR bands) to formate ions (according to the 1595, 1357, 1380 cm(-1) upward IR bands) and water (according to the 3427 cm-1 of v(H-) 0 upward IR band) in heavy water solution. The results illustrated that formaldehyde formed gem-dial anion in alkaline solution and was absorbed on the electrode surface; then gem-diol anion was oxidized to formate ions and water. (C) 2013 Bao-Kang Jin. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.