Surface reactivity of Li2MnO3: Structural and morphological impact.

• Experimental-theoretical study: XPS, gaseous probe adsorption, DFT calculations. • The periodicity of the potential energy is not broken by the stacking fault. • Stacking faults do not impact the surface electronic structure. • Surface reactivity is governed by the morphology and the manganese environments. This paper investigates the role of the stacking fault (5%, 20% and 50%) and the morphology of Li 2 MnO 3 lamellar materials, issued from coprecipitation method with three annealing temperatures, on the surface reactivity. The structure and the morphology have been characterized by XRD, SEM and TEM. We studied the surface reactivity of these materials by combining X-ray photoemission spectroscopy (XPS), gaseous adsorption and first-principle calculations. An evolution of the reactivity toward the SO 2 acid gaseous probe has been observed for the three materials, from pure redox mechanism toward mixed acid-base/redox mechanisms, respectively for 5% and 50% of stacking faults. We demonstrated that the electronic structure of Li 2 MnO 3 being not modified by stacking faulted. Thus, the surface reactivity of faulted Li 2 MnO 3 is not linked to the SF rate but only governed by the accessible crystalline surfaces and the manganese environments at the surface atomic layer. The formation of (0 0 1)-Li surface according to the Li-overstoichiometry on the extreme surface and the random particles shape of the more faulted materials are responsible of the reactivity tuning. [ABSTRACT FROM AUTHOR]