High-Performance Ir 1 /CeO 2 Single-Atom Catalyst for the Oxidation of Toluene.

The elimination of toluene is an obligatory target with increasing VOC emission in recent years. This study successfully prepared a single-atom Ir catalyst (Ir 1 /CeO 2 ) by a simple incipient wetness impregnation method, confirmed by in situ CO DRIFTS and AC-HAADF-STEM. Compared to the cluster Ir catalyst (Ir/CeO 2 -C), Ir 1 /CeO 2 exhibited excellent catalytic performance, stability, and water resistance for the oxidation of toluene. By Raman, H 2 -TPR, O 2 -TPD, and XPS experiments, abundant oxygen defects and a unique Ir 3+ -Ov-Ce 3+ structure were formed for the Ir 1 /CeO 2 sample because it had a lower oxygen vacancy formation energy. Furthermore, the DFT results revealed that the Ir 1 /CeO 2 sample had a lower ring-opening energy barrier and adsorption energy of the ring-opening products, which was the rate-determining step for the oxidation of toluene. This work provides instructive insights into the construction of Ir/CeO 2 catalysts for the highly efficient removal of VOCs.