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If a reaction occurs through these steps: A + S ⇌ AS → Products. where A is the reactant and S is an adsorption site on the surface and the respective rate constants for the adsorption, desorption and reaction are k 1, k −1 and k 2, then the global reaction rate is:
Response surface methodology uses statistical models, and therefore practitioners need to be aware that even the best statistical model is an approximation to reality. In practice, both the models and the parameter values are unknown, and subject to uncertainty on top of ignorance.
where p A is the partial pressure of A over the surface, [S] is the concentration of free sites in number/m 2, [A ad] is the surface concentration of A in molecules/m 2 (concentration of occupied sites), and k ad and k d are constants of forward adsorption reaction and backward desorption reaction in the above reactions.
The solid-state reaction route is the most widely used method for the preparation of polycrystalline solids from a mixture of solid starting materials. Solids do not react together at room temperature over normal time scales and it is necessary to heat them to much higher temperatures, often to 1000 to 1500 °C, in order for the reaction to occur at an appreciable rate.
In the field of solid catalysis, the surface area of catalysts is an important factor in catalytic activity. Inorganic materials such as mesoporous silica and layered clay minerals have high surface areas of several hundred m 2 /g calculated by the BET method, indicating the possibility of application for efficient catalytic materials.
These reactions are very exothermic due to the formation of stable Si–F bonds. [25] Metals deposited by fluorosilane elimination include tungsten [32] and molybdenum. [33] As an example, the surface reactions for tungsten metal ALD using WF 6 and Si 2 H 6 as the reactants can be expressed as [32] [34] WSiF 2 H* + WF 6 → WWF 5 * + SiF 3 H
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In chemistry, catalytic resonance theory was developed to describe the kinetics of reaction acceleration using dynamic catalyst surfaces. Catalytic reactions occur on surfaces that undergo variation in surface binding energy and/or entropy, exhibiting overall increase in reaction rate when the surface binding energy frequencies are comparable to the natural frequencies of the surface reaction ...