In situ gravimetric studies of the regenerative mechanism for water‐gas shift over magnetite: Equilibrium and kinetic measurements in CO2/CO and H2O/H2 gas mixtures

In situ gravimetric measurements were used to study oxygen removal from (or incorporation into) chromia‐promoted magnetite in CO2/CO and H2O/H2 gas mixtures at 637 K. The equilibrium and kinetic data could be described by two reversible, oxidation‐reduction reactions: surface‐oxygen removal by CO and surface oxygen replenishment by H2O, with the corresponding reverse reaction involving CO2 and H2. These reactions form a regenerative mechanism that is able to predict qualitatively both the measured rate and rate expression for water‐gas shift. It is concluded that this regenerative mechanism is a primary pathway for water‐gas shift over magnetite.