The conversion kinetics and adsorption potential of molecular hydrogen probed by energy-dispersive neutron imaging

The study and characterisation of the physical adsorption of molecular hydrogen in porous materials is of primary interest for efficient and green transport technology. Adsorption zero-point energy, only recently included in state-of-the-art computer simulations, reduces the H2 uptake levels. Following some preliminary results, based on neutron transmission and neutron Compton scattering at the VESUVIO spectrometer, we suggest that the adsorption zero-point energy, increasing the kinetic energy of the molecule's centre of mass, changes the temperature-dependent concentrations of the para- and ortho- modifications of molecular hydrogen. Given the exquisite sensitivity of neutrons to the difference in the cross sections of the two forms, we suggest that energy-dispersive neutron imaging can be used as a spectroscopic probe to reconstruct the hydrogen-adsorption potential energy surface.