Kinetics of Intercalation in Lamellar Hosts Using Time-Resolved X-Ray Diffraction

Abstract

Some of the earliest and most extensive studies of the kinetics of intercalation reactions were first carried out using graphite crystals. In these early classic experiments, for example those by Hooley and co-workers [1,2], they investigated the gain in weight of a graphite flake under a bromine atmosphere. Until recently only two time-resolved diffraction studies on metal chalcogenide the intercalation have reported. [3–7] One of these pioneering studies by Riekel and Schollhorn measured time-resolved neutron diffraction data during the intercalation of 2H-TaS2 with NH3(g). However, the available levels of beam flux, whilst high by neutron standards, necessitated either very large sample sizes (~15g) or long acquisition times, making a thorough, quantitative study under varying reaction conditions of temperature, concentration and particle size unfeasible. Moreover, because of the large incoherent scattering from hydrogen atoms by neutrons, the samples studied had to be highly deuterated, an expensive and not always achievable prerequisite for other intercalation reactions. Even taking all these previous experiments into consideration we still have a fairly rudimentary understanding of the intimate mechanism of these reactions. The critical factors which control the rates of these reactions are still based on trial and error experiments. We still commonly use the schematic illustration shown in Figure 1 to describe these reaction which undoubtedly greatly oversimplifies the true picture.KeywordsGuest MoleculeHost LatticeGraphite FlakeMetal ChalcogenideIntercalation ReactionThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.