Eley-Ridel

The desire to understand catalytic chemistry was one of the motivating forces underlying the development of surface science. In a catalytic reaction, the reactants first adsorb onto the surface and then react with each other to fonn volatile product(s). The substrate itself is not affected by the reaction, but the reaction would not occur without its presence. Types of catalytic reactions include exchange, recombination, unimolecular decomposition, and bimolecular reactions. A reaction would be considered to be of the Langmuir-Hinshelwood type if both reactants first adsorbed onto the surface, and then reacted to fonn the products. If one reactant first adsorbs, and the other then reacts with it directly from the gas phase, the reaction is of the Eley-Ridel type. Catalytic reactions are discussed in more detail in section A3.10 and section C2.8. 

Kuipers E W, Vardi A, Danon A and Amirav A 1991 Surface-molecule proton transfer—a demonstration of the Eley-Ridel mechanism Phys.Rev. Lett. 66 116... 

The most acknowledged reaction mechanism for the NO + NH3 reaction (Rl) over the vanadia SCR catalyst is a dual-site Eley-Ridel mechanism proposed by Inomata et al. [25] and Miyamoto et al. [20]. A simplified description of the... 

The Eley-Ridel mechanism shown in Fig. 3.5 describes well the reaction (Rl) at operating temperatures T > 280 °C [26]. At lower temperatures, however (T < 250 °C), NH3 can inhibit the SCR-reaction [26, 27], an effect that cannot be explained by the mechanism in Fig. 3.5. Nova et al. [26, 27] proposed that at low temperatures the reaction proceed through a modified redox kinetics NH3 can adsorb to two types of sites, one redox site associated with vanadyl species and one nonreducible strongly acidic site. The inhibition of the SCR reaction can occur by NH3 blocking part of the active catalyst sites from the redox cycle. 

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