Insight Into the Effect of Oxygen Vacancies in Cu/TiO ₂ With Different Crystal Phases on CO Oxidation

Abstract The development of efficient catalysts for CO oxidation is crucial for emission control in the iron and steel industry. In this study, we prepared a series of Cu/TiO 2 catalysts by the impregnation method. Cu/TiO 2 ‐H600 (TiO 2 pretreated with H 2 /N 2 at 600 °C) in the anatase phase and Cu/TiO 2 ‐H900 (TiO 2 pretreated with H 2 /N 2 at 900 °C) in the rutile phase both showed better CO oxidation activity (T 90 = 222 °C and 216 °C) than that of Cu/TiO 2 without support pretreatment (T 90 = 274 °C). Through a series of characterization techniques, it was concluded that the Cu/TiO 2 ‐H600 and Cu/TiO 2 ‐H900 catalysts possessed more oxygen vacancies than Cu/TiO 2 ; notably, it was found that the dominant promotion mechanisms of oxygen vacancies in Cu/TiO 2 ‐H600 and Cu/TiO 2 ‐H900 for CO oxidation were different from each other. The role of oxygen vacancies in the Cu/TiO 2 ‐H600 is inducing the activation of surface lattice oxygen to take part in CO oxidation, while that in Cu/TiO 2 ‐H900 is dissociating gaseous oxygen to participate in CO oxidation. This study provides guidance for understanding the role of oxygen vacancies in CO oxidation and is helpful to the design of Cu/TiO 2 catalysts with high‐efficiency CO oxidation activity.