RWGS reaction

Methanol synthesis from C02 (Equation [1]) and CO (Equation [2]) is mildly exothermic and results in volumetric contraction. Methanol steam reforming (MSR) refers to the inverse of reaction (1), and the inverse of reaction (2) is conventionally referred to as methanol decomposition - an undesired side reaction to MSR. The slightly endothermic reverse water-gas shift (rWGS) reaction (Equation [3]) occurs as a side reaction to methanol synthesis and MSR. According to Le Chatelier s principle, high pressures and low temperatures would favor methanol synthesis, whereas the opposite set of conditions would favor MSR and methanol decomposition. It should be noted that any two of the three reactions are linearly independent and therefore sufficient in describing the compositions of equilibrated mixtures. 

Several studies are available addressing the mechanism and kinetics of the MSR reaction over Cu-based catalysts [115-121], There is agreement nowadays that C02 is a direct product of the MSR reaction and not of a sequence of methanol decomposition and WGS reactions. The main source of CO is the rWGS reaction taking place as a secondary reaction after MSR. Frank et al. [121] presented a... 

We have previously shown that the kinetics of the reverse water gas shift (RWGS) reaction can be modelled on the basis of a simple redox mechanism (1). This result contradicted an earlier assertion deriving from a kinetic analysis of the reaction which claimed that the reaction proceeded through a formate intermediate (2). The individual elementary reactions of the redox mechanism, which in combination constitute the overall reaction, are listed in table 1, together... 

Reaction 5.9 shows no CO formation in the reforming process. However, some CO will form through the reversed water-gas shift (RWGS) reaction according to Reaction 5.10. 

Scheme 3.11 Mechanism of the Ru-catalyzed reversed water gas shift (RWGS) reaction.

The second way to obtain ammonia during the NSR regeneration is the isocyanate route [23]. This intermediate reaction is observed when a carbon source is present in the reaction mixture, especially CO [11]. However, CO can also be produced in situ, for instance by the reverse water gas shift (RWGS) reaction between H2 and CO2, the later being always present in large amounts in a real exhaust gas (see also the influence of the WGS equilibrium Sect. 19.2.3). 

The poisoning effect of CO2 is mainly due to fhe formation of CO by the RWGS reaction and the electro-reduction of CO2 by Pf hydrides at low potentials. Review of fhe CO2 reaction kinetics and performance effects are discussed. 

The shaded area in the stripping graph of Figure 4.6(a) stands for the oxidation of Pt-CO, which is produced during the 10 h exposure to 50%C02/50%H2. It is the direct proof for the sentence of RWGS reaction. The Pt-CO formed by electro-reduction of CO2 polarizes HOR in the same manner as Pt-CO formed by direct CO adsorption. Therefore, in the following section, the impact of CO will be focused on the impact of CO. 

The Pt-CO bond created by the reduction of carbon dioxide affects hydrogen electrooxidation in the same manner as the Pt-CO formed via CO2 reduction. Although, the reduction of carbon dioxide polarizes hydrogen electrooxidation, more studies are tailored to understanding the reverse water-gas shift (RWGS) reaction and its effects. The WGSR is ... 

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