Electrooxidation of Dimethoxymethane on a Platinum Electrode in Acidic Solutions Studied by in Situ FTIR Spectroscopy

Electrooxidation of dimethoxymethane (DMM, H₂C(OCH₃)₂), a promising alternative fuel to methanol in direct fuel cells, on a Pt electrode in acidic solutions was studied by in situ Fourier transform infrared (FTIR) reflection spectroscopy. The study revealed that the dissolved products of DMM oxidation are mainly methyl formate (MF, HCOOCH₃), methanol and CO₂, and the adsorbed species are linearly bonded CO (CO_L) that are derived from the further dissociative adsorption of methanol. The variation of products involved in DMM oxidation at different electrode potentials was analyzed quantitatively from in situ FTIR spectra. The results demonstrated that the MF and methanol are preferentially generated at low potentials or in the initial stage of DMM oxidation, while CO₂ dominates at high potentials or in the final oxidation step. On the basis of experimental results, a reaction mechanism of DMM oxidation on Pt electrode was suggested at molecular level.