Hydrogen species in cerium—nickel oxides catalysts: Inelastic and Compton Neutron Scattering Studies

Abstract

Publisher Summary This chapter describes the combined neutron compton scattering (NCS) and inelastic neutron scattering (INS) measurements to characterize hydrogen species stored in the reduced solids and studies the stability and the reactivity of these hydrogen species in CeNi x oxides. Neutron spectroscopies are very sensitive techniques for the characterization of hydrogen containing molecules. For the studies of hydrogen species in Nickel–Cerium catalysts, INS is attractive because INS strongly emphasizes the motions of hydrogen species. The scattering cross-section is much greater for hydrogen (80 barns) than for other elements (5 barns). This technique allows the identification of SH group in MoS 2 based catalysts. NCS consists in measuring atomic momentum distributions and hence kinetic energies of the neutron scattered by the studied sample. Hydrogen has the greatest cross-section. The attraction of NCS is, therefore, its sensitivity toward hydrogen (limit of detectivity: 0.5% H). The NCS was recently used to reveal the presence and chemical environment of hydrogen in hydrodesulfurization based catalysts, solids that are known as being also “hydrogen reservoir.”