1 research outputs found
Bridging the Catalyst Reactivity Gap between Au and Cu for the Reverse Water–Gas Shift Reaction
The reverse water–gas shift reaction (rWGSR) is
highly relevant
for CO2 utilization in sustainable fuel and chemical production.
Both Au and Cu are interesting for rWGSR catalysis, but it turns out
that the reactivities of Au and Cu are very different. In this study,
we consider alloys made from Au, Ag, Cu, Pt, and Pd to identify surfaces
with reactivities for CO2 dissociation between Cu(111)
and Au(111). Additionally, interesting alloy surfaces should have
activation energies for CO2 dissociation that are only
a little higher than the endothermic reaction energy. We find that
certain Cu-based alloys with Ag and Au meet these criteria, whereas
alloys containing Pt or Pd do not. The low additional cost in activation
energy occurs when the transition-state and final-state configurations
are made to look very similar due to the placement of the different
metal elements on the surface. Finally, we construct a kinetic model
that compares the rate of the rWGSR to the estimated rate of unwanted
side reactions (i.e., methane formation or coking) on Ag–Cu
alloy surfaces with varying compositions and random placement of the
Ag and Cu atoms. The thermodynamics favor methane formation over rWGSR,
but the model suggests that Ag–Cu alloy surfaces are highly
selective for the rWGSR