New Catalytic Systems Based of Nanoparticles of Group 1B Metals for Low-Temperature ortho–para-Hydrogen Conversion

In relation to low temperature ortho–para-hydrogen conversion in the low-pressure range, the catalytic activity of systems based on Cu, Ag, and Au nanoparticles supported on γ-Al2O3 and bimetallic nanoparticles of the Cu–Ag and Au–Ag systems, as well as industrial Ni/Al2O3 and α-Fe2O3 samples, was determined. The ortho–para-conversion reaction on nanoparticles of group 1B metals occurs via a magnetic mechanism. Monometallic nanoparticles showed a higher activity than industrial samples. Cu and Ag demonstrated a pronounced synergistic effect during interaction. The catalytic activity of the copper-based sample with the addition of silver exceeds by more than 2 times the activity of the individual metal particles that form it and by 3 and 9 times the activity of the Ni/Al2O3 and α-Fe2O3 samples, respectively. The obtained data indicate the potential of Cu- and Ag-based bimetallic nanoparticles for low-temperature ortho–para-hydrogen conversion; however, research into their catalytic properties in the high-pressure range is necessary.