Selective Oxidation of C-H Bonds Raw Materials Change in Chemical Industry and Efficient Energy Storage Introduction Model studies of C-H Activation Objectives and strategy Deeper understanding of the structural dynamics of the active sites and the entire catalyst material Theoretical and experimental investigation of the interactions of catalyst and reaction dynamics Identification of key factors controlling the performance of catalysts Design of catalysts with adjustable “smart” surface properties Immediate transfer of promising catalysts and process concepts to application Highlights Oxidative coupling of CH4 on Li-doped and non-doped MgO The calculated energy barriers for CH4 activation by hydrogen abstraction at oxygen radical sites of Li-doped MgO are unrealistically low. Lundsford mechanism needs to be revised Temperature programmed reaction experiments: the same active sites are responsible for activation of methane on both Li-doped MgO and pure MgO catalysts. Highlights The multi-scale approach of UNICAT to the oxidative coupling of methane made substantial achievements for the fundamental understanding of simplest OCM catalyst and the development of promising catalyst and process for industrial application. Revision of the long-time established “Lunsford”-mechanism Detailed understanding of the contribution of gas phase reactions Proposal of new activation mechanism at non-reducible oxide surfaces Revealing of fluctuations in composition and shape of catalyst surface by in-situ structural studies at model systems Substantial improvement of mixed hetero-metallic NaMnSi oxide catalyst by advanced preparation methods Identification of different oxygen species involved in selective and in selective reaction pathways Development of optimized reactor concepts on the basis of comprehensive kinetic models Conception and validation of new OCM process on mini-plant level Measurements for differently prepared pure MgO catalysts suggest that the catalytic activity originates from morphological defects. The activity proved to be very different in the initial phase of the OCM reaction and in the steady state. Substantial morphological changes and restructuring of the terminations as transmission electron microscopy revealed. 0 h 66 h New mechanism proposed: Methane binds heterolytically on Mg2+O2- sites at steps and corners, and methyl radicals are released into the gas phase when O2 is present on the surface. The role of the catalyst surface is to bind CH4 and O2 which exchange redox equivalent directly among themselves, but not with the catalyst. Modes of dynamics in catalysis with novel aspects of chemical and structural dynamics Kwapien, Paier, Sauer, Geske, Zavyalova, Horn, Schwach, Trunschke, Schlögl, Angew. Chem. Int. Ed., 2014, 53, 8774 Activation of O2 at model catalysts Kinetic Investigations of Gas Phase Reactions Highlights Charge transfer from Mo donor ions stimulates the formation of superoxo-species on the surface of a wide-gap CaO film. Formation of pre-dissciated O2- species Final dissociation via electron tunneling from STM tip Highlights A profile reactor with on-line MS analysis allows spatial resolution of reactant and product concentrations in catalyst beds as well as free gas phase Coupling of methane to C2-products without catalysts Lag period for establishment of radical pool Strong pressure dependence of selectivity Objectives and strategys Characterize different oxygen species on the catalyst surface by joint experimental – computational work Use computational methods to explore the role of different oxygen species in the complex reaction mechanism Objectives Extention of profile reactor studies to other hydrocarbon oxidation reactions and combination with in-situ studies of catalyst surface Microkinetic model for homogeneous gas phase reactions Two dimensional reactor modeling with CFD tool for model validation R. Horn, O. Korup, M. Geske, U. Zavyalova, I. Oprea, R. Schlögl , Review of Scientific Instruments 2010, 81, 64102 Cui, Shao, Baldowski, Sauer, Nilius Freund, Angew. Chem. Int. Ed., 2013, 52, 11385 Synthesis of Mn/Na2WO4/SBA-15 Reactor concepts Objectives Investigation of structural dynamics Correlation of performance and dynamics Identification of tuning parameters for dynamic properties Comparison of phase pure and complex phase catalysts Highlights Detailed mechanistic studies and kinetic modeling of OCM Simulation studies for OCM in Fixed Bed, Fluidized Bed and Membrane Reactor Derivation of optimized feed strategies Validation of catalysts performance with up to 200 g catalyst C2-Yield of 25,5 % at 80 % selectivity Concepts for integrated OCM/DRM reactor silica support pre-catalyst catalyst commercial Impregnation Calcination Na2WO4 · 2 H2O 750°C Mn(ac)2 ·4 H2O X Mn-Na2WO4/SBA-15 Mn-Na2WO4/SBA-15 Scheme of fluidized bed reactor and OCM performance data S. Jaso et al., J. Nat. Gas Chem., 2012, 21 534-543 nanostructured (SBA-15) Mn-Na2WO4/ commercial silica Up-scaling of catalyst synthesis Objectives Design of reactors and operation strategies by simulation studies with comprehensive kinetic models Design and optimization of membrane fluidized bed reactor Utilization of instationary operation conditions Highlights Highly homogeneous dispersion of active components over SBA-15 Increased activity due to higher dispersion of Mn/Na2WO4 Increased selectivity due to reduced number of non-selective sites at uncovered support material Improved stability Testing on lab scale C2-Yield= 12 % Validation in Miniplant C2-Yield= 25,5 % Scheme of membrane reactor and performance data M. Yildiz, Y. Aksu, U. Simon, K. Kailasam, O. Goerke, F. Rosowski, R. Schomäcker, A. Thomas, S. Arndt Chem. Commun. 2014, 50, 14440 H. R. Godini, et al. Energy & Fuels 2013, 1312 Harnessing the Methodological Toolbox Process Design and Validation in Mini-Plants Highlights Successful scale-up of OCM to a mini-plant Yield of 25,5 % at 80 % selectivity in mini-plant 50 % energy saving in down-stream processing by hybrid separation process Concepts for process integration of OCM and DRM Physical methods for structure analytical studies Chemical Microscope EMIL Vibrational spectrodscopy for identifying adsorbates EPR spectroscopy for high spin metal centers Solid-state NMR with dynamic nuclear polarization (DNP) X-Ray adsorption spectroccopy for direct tracking of structural changes New Reactor concepts Chemical Looping for partial oxidation reactions Feed strategies for separation of competitive reactions Challenges for fluid dynamics and process control Objectives Investigation of different equipment alternatives Dynamic behavior of reactors under recycle conditions Integration of reactors with instationary operation mode Conventional design of OCM process Steam Generator Refrigerant Compressor Reactor Compressor CO2 Absorption Cryogenic Distillation C2 CO2 CH4, CO, H2 Air Blower Steam Generator Reactor Adsorptive Separation CO2 Absorption C2 Dynamical terminating graphene layer at bulk copper metal (green lines in right image) followed by the home-developed in-situ ambient pressure SEM. CH4, CO, H2 CO2 Flow diagram of new OCM process Scheme of Chemical Looping operation of fixed bed reactors Scheme of alternative OCM process without compressor H. R. Godini, et.al. Technical Transactions 2012, 5, 63–74 D2/E2