Enhanced Catalytic Conversion of Ortho-Hydrogen to Para-Hydrogen by using Iron- Cobalt Bimetallic Catalysts

Abstract The catalytic conversion of ortho-hydrogen (o-H₂) to para-hydrogen (p-H₂) serves as a crucial step in the storage of liquid hydrogen over extended periods. A variety of iron-cobalt catalysts were synthesized using a precipitation technique, incorporating diverse levels of Co doping into Fe-based catalysts. The effects of Co doping on the crystal structure, porosity, and magnetism of FCO were examined through XRD, N₂ adsorption-desorption, FTIR, XPS, and VSM analyses. The efficacy of ortho-para hydrogen conversion within FCO at 77 K was analyzed using chromatography. Findings revealed that Co doping enhances the material’s lag coefficient, leading to an increase in active sites and larger magnetic moments. Notably, FCO-5 [n(Fe)/n(Fe + Co) = 0.5] exhibited the most efficient ortho-para hydrogen conversion performance. Specifically, at GHSV = 5400 h⁻ ¹, FCO-5 achieved a reaction rate constant of 291.7 mol·L⁻ ¹·s⁻ ¹, a conversion rate of 99.24%, and a post-conversion p-H₂ content of 49.7%.