Abstract:

Ortho to para hydrogen conversion catalyst (O-P catalyst) is integral for large-scale hydrogen liquefaction projects. However, factors that influence catalyst performance remain preliminary and unclear. In the mean time, the mechanical strength of the O-P catalyst is crucial for its efficacy and longevity, yet most related research has paid sufficient attention to the catalytic activity. In this work, an iron-based O-P catalyst was synthesized using a straightforward precipitation method. And effects of catalyst activation method, drying temperature, particle size, concentration ratio, and doping element on catalytic activity and mechanical strength were studied. Furthermore, the catalytic performance and structural characterization of the prepared catalyst and commercial catalyst were compared. The prepared catalyst achieved a para hydrogen (p-H₂) content of 46.49% post-conversion at 77 K with a hydrogen flow rate of 1200 mL/min, surpassing the commercial catalyst by 2.9%. The maximum single particle crushing force of the prepared catalyst reached 4.75 N. Therefore, a preliminary mechanism for enhancing catalytic activity optimization was elucidated, offering valuable insights into ortho to para hydrogen conversion, and this study provides foundational data supporting the scaled production of domestic catalysts.

Key words: ortho to para hydrogen conversion, iron-based catalyst, catalytic performance