Elucidating the Nature of the Cu(I) Active Site in CuO/TiO₂ for Excellent Low-Temperature CO Oxidation

Abstract

Stabilized Cu+ species have been widely considered as catalytic active sites in composite copper catalysts for catalytic reactions with industrial importance. However, few examples comprehensively explicated the origin of stabilized Cu+ in a low-cost and widely investigated CuO/TiO2 system. In this study, mass producible CuO/TiO2 catalysts with interface-stabilized Cu+ were prepared, which showed excellent low-temperature CO oxidation activity. A thorough characterization and theoretical calculations proved that the strong charge-transfer effect and Ti–O–Cu hybridization in Ti-doped CuO(111) at the CuO/TiO2 interface contributed to the formation and stabilization of Cu+ species. The CO molecule adsorbed on Cu+ and reacted directly with Ti doping-promoted active lattice oxygen via a Mars–van Krevelen mechanism, leading to the enhanced low-temperature activity.

Photocatalytic CO2 Reduction and Thermal CO Oxidation to CO2 over Cu/Ni-loaded TiO2 Photo and Thermal Catalysts

“…The concentration for the 5 mol% sample exhibited the sharpest changes at different temperatures. For bare TiO 2 NPs, no CO oxidation activity was observed below 500 °C, which is in good agreement with the literature [14]. For the CO oxidation profiles obtained using temperature-programmed reaction spectrometry, the sample heating rate was fixed at 20 K/min.…”

“…For thermal CO oxidation tests [7,14,15], Fang et al prepared CuO/TiO 2 catalysts using coprecipitation and impregnation methods and reported a CO oxidation onset at approximately 50 °C [14]. The high catalytic activity was attributed to the interfacial bond formation of hybrid Ti O Cu and the consequent stabilization of Cu + species.…”

New insights into the influence mechanism of H2O and SO2 on Pt–W/Ti catalysts for CO oxidation

“…The commonly used catalysts for CO oxidation are divided into noble metal catalysts such as Pt, 7,8 Au, 9–12 Pd, 13 Ag, 14 Ru, 15 Rh, 16 and Ir (ref. 17) and transition metal catalysts such as Cu, 18–21 Co, 22–25 and Mn. 26,27 In the reaction atmosphere (CO and O 2 ), the noble metal catalysts commonly show a higher CO catalytic activity than transition metal catalysts, whereas the drawback of high cost is a major limit for their wide applications.…”

Solid-State Construction of CuOx/Cu1.5Mn1.5O4 Nanocomposite with Abundant Surface CuOx Species and Oxygen Vacancies to Promote CO Oxidation Activity

“…Many techniques, such as morphology control [ 4 , 5 , 6 , 7 ], engineering defects [ 8 , 9 , 10 ], and construction of composite oxides [ 11 , 12 , 13 ] have been developed to improve the CO oxidation performance of transition metal oxide catalysts. Particularly, heterogeneous metal oxides that have exhibited excellent performances in CO oxidation fields [ 14 , 15 , 16 ] are the most widely studied because of their interactions of components [ 17 ]. Previous works have gradually demonstrated that heterogeneous metal oxides with synergistic interactions between two components are crucial for promoting catalytic performances [ 12 , 18 , 19 ].…”