Probing the factors affecting structure and activity of the Au/CeO2 system in total and preferential oxidation of CO

The effects of the preparation method (deposition–precipitation, co-precipitation, incipient-wetness, combustion) and loading (1–5 wt.%) on the structure and redox features of the Au/CeO2 system have been probed by XRD, TEM and TPR techniques. The catalytic pattern in total (TOX) and preferential (PROX) CO oxidation has been assessed by temperature programmed reaction tests in the range 273–473 K. Controlling surface area and residual chlorine, the synthesis route determines the strength of the Au–CeO2 interaction which, reflecting in a hard reduction of the active phase, hinders the CO oxidation functionality. Chlorine removal by washing treatment in diluted alkaline solutions enables an easy reduction of the active phase, levelling off the TOX and PROX performance of the various systems.