In-situ DRIFTS study of chemically etched CeO2 nanorods supported transition metal oxide catalysts

In this work, hydrothermally synthesized CeO2 nanorods (CeO2NR) were chemically etched by strong reducing agent NaBH4 with 0.6~30 wt% addition, and further transition metal (TM) oxides (TM: Cu, Co, Ni, Fe and Mn) were loaded on the surface modified 6 wt% NaBH4CeO2NR powder (mCeO2NR) to prepare mCeO2NR supported TM oxide catalysts. Both mCeO2NR supports (treated by 0.6–30 wt% NaBH4) and mCeO2NR supported TM oxide catalysts were employed to investigate the effect of chemical etching on their surface structure, CO adsorption, CO2 desorption and catalytic performance. Compared with pristine CeO2NR, one strong CO adsorption band for polydentate carbonate is found from in situ DRITFS as a result of NaBH4 etching, which can explain the enhanced low temperature reducibility and catalytic performance of mCeO2NR supports and mCeO2NR supported TM oxide catalysts. The vibrational band signals of bicarbonate, monodentate/bidentate/polydentate carbonate and bridged carbonate are detected in all mCeO2NR supported TM catalysts and the effect of CO adsorption mode on CO oxidation activity is discussed.