SIMULTANEOUS MEASUREMENTS OF SURFACE INTERMEDIATES AND STEP VELOCITIES DURING THE WATER-GAS-SHIFT REACTION OVER AN IRON OXIDE CATALYST

The kinetics of the water-gas-shift reaction over an iron oxide catalyst has been studied with the transient tracing technique. The transient tracing technique was confirmed to be a new methodology of simultaneous measurements of adsorption and kinetics. The rate of the step, H₂O→ 2H(a) + O(a), was observed to be about ten times larger than that of the step, 2H(a) → H₂. The amount of adsorbed hydrogen obtained was 1.7 × 10²⁰ atoms/g-cat in agreement with that determined by the volumetric method during reaction.