Copper oxide catalyst supported on niobium oxide for CO oxidation at low temperatures

• Published in: Catalysis communications 2017-07, Vol.97, p.42-46
• Main Authors: Leung, Emi, Shimizu, Akiko, Barmak, Katayun, Farrauto, Robert
• Format: Article
• Language: English
• Subjects: Copper impregnation on niobium oxide; Enhanced CO oxidation activity; Niobium promotional effect on copper oxide; Stabilized Cu(I) species on niobium oxide
• ISSN: 1566-7367; 1873-3905
• DOI: 10.1016/j.catcom.2017.04.008

CuOx/Nb2O5 shows higher CO oxidation activity than CuOx/Al2O3. Analysis of X-ray photoelectron spectra shows the presence of Cu1+ species on Nb2O5, which is known to be the active species for CO oxidation. In contrast, only Cu2+ is found to be present on Al2O3. Enhanced activity of CuOx/Nb2O5 is consistent with its lower activation energy for CO oxidation compared with CuOx/Al2O3. It is argued that the formation of stable Cu1+ species on Nb2O5 is a result of presence of deep copper acceptor states within the band gap of Nb2O5. 6%CuOx/Nb2O5 shows comparable activity to 1%Pt/Al2O3 but loses its advantage above 500°C. [Display omitted] •Cu-impregnated Nb2O5 shows enhanced CO oxidation activity compared to Cu-impregnated Al2O3.•Lower activation energy of 6%CuO/Nb2O5 than 6%CuO/Al2O3 is confirmed.•Enhancement of the CO oxidation activity is caused by Cu1+ species on Nb2O5.•6%CuO/Nb2O5 shows comparable CO oxidation activity to 1%Pt/Al2O3.