Effect of supercritical water on redox cycle capability of iron oxide duringdecomposition of formic acid

Formic acid (FA) has great potential as an in situ source of hydrogen, because it offers highenergy density, and can be safely handled in aqueous solution. In the current study,decomposition of formic acid (H2+CO2←HCOOH→CO+H2O) was investigated in thesupercritical water (W) medium over iron oxide nanoparticle in order to shift the conversiontoward more hydrogen production through water-gas shift reaction (CO+ H2O↔ H2+ CO2). Thisreaction can be accelerated through the redox mechanism (Fe+3↔Fe2+) in which supercriticalwater has a positive effect on this cycle. The effects of parameters (temperature, water densityand FA/W ratio) were investigated on the catalyst structure and gas composition. From X-raydiffraction (XRD), electron diffraction (ED) analysis of catalyst as well as gas chromatographicanalysis (GC) of gas composition (CO, CO2, H2, CH4), it was revealed that water pressure haspositive effect on stability of catalyst and modification of selectivity toward more H2 production.The pathway of the reaction can be seen at the following.

کلیدواژه ها:

Redox cycle ، Iron oxide ، Supercritical water ، Formic acid