Including lateral interactions into microkinetic models of catalytic reactions.
نویسندگان
چکیده
In many catalytic reactions lateral interactions between adsorbates are believed to have a strong influence on the reaction rates. We apply a microkinetic model to explore the effect of lateral interactions and how to efficiently take them into account in a simple catalytic reaction. Three different approximations are investigated: site, mean-field, and quasichemical approximations. The obtained results are compared to accurate Monte Carlo numbers. In the end, we apply the approximations to a real catalytic reaction, namely, ammonia synthesis.
منابع مشابه
Adlayer inhomogeneity without lateral interactions: rationalizing correlation effects in CO oxidation at RuO2(110) with first-principles kinetic Monte Carlo.
Microkinetic modeling of surface chemical reactions still relies heavily on the mean-field based rate equation approach. This approach is expected to be most accurate for systems without appreciable lateral interactions among the adsorbed chemicals, and there in particular for the uniform adlayers resulting in poisoned regimes with predominant coverage of one species. Using first-principles kin...
متن کاملAdsorbate interactions on surface lead to a flattened Sabatier volcano plot in reduction of oxygen
Ab initio electronic-structure calculations of surface catalysis often give changes P0.1 eV for activation energies of intermediate steps when the surface structure or composition is varied, yet P50-fold change in activity according to naive interpretation of the Arrhenius formula is usually not seen in corresponding experiments. To quantitatively analyze this sensitivity inconsistency between ...
متن کاملParallel kinetic Monte Carlo simulation framework incorporating accurate models of adsorbate lateral interactions.
Ab initio kinetic Monte Carlo (KMC) simulations have been successfully applied for over two decades to elucidate the underlying physico-chemical phenomena on the surfaces of heterogeneous catalysts. These simulations necessitate detailed knowledge of the kinetics of elementary reactions constituting the reaction mechanism, and the energetics of the species participating in the chemistry. The in...
متن کاملProcess Simulation for the Design and Scale Up of Heterogeneous Catalytic Process: Kinetic Modelling Issues
Process simulation represents an important tool for plant design and optimization, either applied to well established or to newly developed processes. Suitable thermodynamic packages should be selected in order to properly describe the behavior of reactors and unit operations and to precisely define phase equilibria. Moreover, a detailed and representative kinetic scheme should be available to ...
متن کاملMicrokinetic analysis of water-promoted CO oxidation, water-gas shift, and preferential oxidation of CO on Pt for hydrogen generation
Hydrogen based proton exchange membranes (PEM) fuel cells show good potential for production of electricity. However, widespread commercialization of PEM fuel cells will depend on cheap and environmentally benign production of hydrogen. Currently, hydrogen is mainly produced from syngas by the water-gas shift (WGS) reaction (CO+H2O↔CO2+H2) followed by preferential oxidation (PROX) of CO. Extens...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- The Journal of chemical physics
دوره 127 19 شماره
صفحات -
تاریخ انتشار 2007