Interacción de la Fe(II)-meso-tetrasulfanatofenilporfirina con moléculas monocarbonadas y su relación con la electroreducción de CO2

The study of the electrocatalytic activity of the Fe(II)-meso-tetraphenylporphyrin tetrasulphonate ([Fe(II)TPPS4]o), towards the redox processes for CO, HCOOH, H2CO y CO2 is reported. The [Fe(II)TPPS4]o seems to form stable species with CO and HCOOH through a coupled chemical reaction, and this species hardly undergoes further oxidation to CO2. Contrary to this behavior, HCOOH and CO2 were readily obtained as oxidation products from H2CO. On the other hand, by means of a spectroelectrochemical study, it was found that CO2 is electrochemically reduced in two consecutive steps; the first step occurs at about -1200 mV, and is attributed to the loss of linearity of CO2 molecule, while the second step, at about 1400 mV, would involve its conversion to formate-like species. The products of CO2 electroreduction were determined by chromatography and include HCOOH, CO and traces of some short chain hydrocarbon species.