Measuring the redox activity of individual catalytic nanoparticles in cerium-based oxides.

We have followed the dynamic redox process taking place in individual ceria zirconia nanoparticles with changes in the oxygen chemical potential using an in situ environmental transmission electron microscopy (ETEM). We observe considerable variability in the redox activity and have been able to correlate these differences with nanoscale structural and compositional measurements. We find that the more active structure has predominantly disordered cations and shows no evidence for oxygen vacancy ordering during reduction.