Probing the internal structure of a cobalt aluminophosphate catalyst. An inelastic neutron scattering study of sorbed dihydrogen molecules behaving as one- and two-dimensional rotors

Analysis of the inelastic neutron scattering rotational spectrum of sorbed dihydrogen in a cobalt aluminophosphate catalyst shows that dihydrogen mole cules confined in the internal space of the CoAlPO behave as 1D rotors, rot ating with the H-H axis aligned with the internal electric field, and as 2D rotors, rotating in a plane and bound sideways at surface sites.