Development of highly effective catalysts for one-stage conversion of light hydrocarbons with high selectivity to valuable products will solve such problems as efficient utilization of natural and oil-associated gases, and environmental protection. Methane dehydroaromatization (DHA) over Mo/ZSM-5 catalysts is a promising process for direct production of valuable aromatic compounds and hydrogen from methane. This review focuses on the range of issues dealing with the effect of catalyst composition, preparation, pretreatment and operation conditions on the physicochemical properties and activities of Mo/ZSM-5 catalysts in DHA reaction. The concepts of the reaction mechanism and the nature of the active molybdenum forms are reviewed. Various aspects of the Mo/ZSM-5 deactivation under reaction conditions and methods of their regeneration are discussed. Some approaches for improvement of the Mo/ZSM-5 performance in DHA reaction are addressed in the review in detail. The perspectives of the methane dehydroaromatization process are also presented.

We report the results from the first 5D tomographic diffraction imaging experiment of a complex Ni–Pd/CeO₂–ZrO₂/Al₂O₃ catalyst used for methane reforming. This five-dimensional (three spatial, one scattering and one dimension to denote time/imposed state) approach enabled us to track the chemical evolution of many particles across the catalyst bed and relate these changes to the gas environment that the particles experience. Rietveld analysis of some 2 × 10⁶ diffraction patterns allowed us to extract heterogeneities in the catalyst from the Å to the nm and to the μm scale (3D maps corresponding to unit cell lattice parameters, crystallite sizes and phase distribution maps respectively) under different chemical environments. We are able to capture the evolution of the Ni-containing species and gain a more complete insight into the multiple roles of the CeO₂-ZrO₂ promoters and the reasons behind the partial deactivation of the catalyst during partial oxidation of methane.