Heterogeneous WGS Catalysts

Modern WGS catalysts can be divided into four classes, namely, HTS, LTS, sour gas shift, and precious-metal-containing catalysts. Iron oxide or iron-chromium mixed oxides promote the WGS in the 350-450 °C range and are modified by MgO or ZnO for good sulfur resistance and mechanical strength. The second type of WGS catalysts are mixed copper-zinc oxides which promote WGS in 

Supported Ionic Liquick Fundamentals and Applications, First Edition. 

Edited by Rasmus Fehrmann, Anders Riisager, and Marco Haumann. 

The redox mechanism involves CO oxidation by surface-adsorbed atomic O [7-10]. Oxygen itself can be obtained by a two-step water dissociation or by a disproportionation of OH. In this case, the hydroxide is formed by hydrogen abstraction from water. In the formate pathway, the adsorbed surface species form a surface intermediate which is subjected to subsequent decomposition into carbon dioxide and hydrogen [11-13]. It involves the interaction between the CO molecule 

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