Ortho- to Para-Hydrogen Spin Conversion Performance of Ho-Fe2O3 Catalytic at 77 K

In the process of hydrogen liquefaction, the conversion of ortho- to para-H2 is necessary to ensure the long-time storage of liquid hydrogen. Ortho- to para-H2 conversion catalysts can accelerate the rate of conversion. In this work, an efficient Ho-F2O3 by a simple precipitation method are developed to catalyze the spin conversion from ortho- to para-H2. Benefiting from the disorder of crystal structure and homogeneity of the nanoparticle distribution after doping with Ho element, Ho-F2O3 has excellent catalytic conversion properties. When the hydrogen flow is 100 mL min−1, the content of para-H2 is 48.67% at 77 K after 1000 min. Our research provides direction for the design of the catalyst.