Water-gas shift reaction: finding the mechanistic boundary

H 2 Production and Fuel Cells

“…In addition to formates, other species such as carbonates and hydroxycarbonates may be participating in the reaction. 15,16 A generally accepted mechanism for the WGS reaction yet fails to exist, and this is not surprising considering the complex nature of the catalyst surface. The need for in-situ characterization under reaction conditions is clear for these systems.…”

“…15 There has been a lot of controversy about what is the active phase and the mechanism of the WGS reaction on these catalysts. 16 Most of the debate resides in the mechanistic area on whether the mechanism is associative taking place through intermediates such as formates or regenerative via redox reactions involving special forms of copper. In addition to formates, other species such as carbonates and hydroxycarbonates may be participating in the reaction.…”

“…CeO 2 -based nanocatalysts have been reported to be very promising for the WGS reaction. Among these materials, the two most studied systems currently are Cu-and Pt-based catalysts 16,17,18,19 . It is anticipated that, with proper development, metal promoted ceria catalysts should realize much higher CO conversions than even commercial CuZnO catalysts 20 .…”

“…The need for in-situ characterization under reaction conditions is clear for these systems. 16 The design of new WGS catalysts is aimed at obtaining systems with a high activity and a lower temperature of operation. 17 At the same time, one has to find a compromise between activity and cost.…”

The water‐gas shift reaction: from conventional catalytic systems to Pd‐based membrane reactors—a review

“…methanation and Fisher-Tropsch processes), reducing selectivity and promoting extra hydrogen consumption. [16] Due to these reasons, the type of pretreatment to be applied to these Fe-Cr catalysts has been the focus of extensive research work. For instance, Gonzalez et al .…”