Effect of shape and composition of steel particles on simultaneous H2 production and CO2 fixation

Abstract

To develop a H₂ production and CO₂ fixation process using scrap iron, the characteristics of iron and steel particles that react efficiently were investigated. The reaction of commercial pure iron and alloyed steel powders were compared, and their reactivity was evaluated based on the specific surface area, apparent density, and crystal lattice strain. The efficient reactivity in porous iron powders was attributed to crevice corrosion. To investigate the effect of alloy composition, we added Ni to pure iron powder by pretreatment, which resulted in enhanced H₂ production and CO₂ fixation. The results indicated that galvanic corrosion contributes to Fe oxidation, because Fe is less noble than Ni based on their electrode potentials. This study provides guidelines for improving the efficiency of reactions that produce H₂ while fixing CO₂ using steel scrap.