Catalytic Decomposition of N2O over Co-Ti Oxide Catalysts: Interaction between Co and Ti Oxide

• Published in: ChemCatChem Vol. 8; no. 12; pp. 2155 - 2164
• Main Authors: Zhang, Chi, Zhang, Zhiping, Sui, Chao, Yuan, Fulong, Niu, Xiaoyu, Zhu, Yujun
• Format: Journal Article
• Language: English
• Published: Weinheim Blackwell Publishing Ltd 21.06.2016; Wiley Subscription Services, Inc
• Subjects: Co-Ti oxides; Decomposition; interaction; N2O decomposition; Spectrum analysis; surface Co3+ species; X-rays
• ISSN: 1867-3880; 1867-3899
• DOI: 10.1002/cctc.201600231

A series of CoxTi catalysts with different Co/Ti molar ratios (x=0.2, 0.4, 0.6, and 0.8) were prepared by the sol‐gel method and used for N2O decomposition. The catalysts were characterized by XRD, X‐ray photoelectron spectroscopy (XPS), TEM, temperature‐programmed reduction with H2, temperature‐programmed desorption of O2, diffuse reflectance UV/Vis, Raman spectra, and N2 adsorption–desorption measurements. The results indicate that the CoxTi catalysts possess high Brunauer–Emmett–Teller (BET) surface area, more surface Co3+, and even better structural stability than Co3O4 as a result of the strong interactions between Co and Ti oxide. Deactivation occurred over time for the Co3O4 catalyst, however, Co0.6Ti maintains nearly 100 % N2O conversion for at least 30 h. Moreover, the Co0.6Ti catalyst showed much stronger resistance against 1.5 vol. % O2, 2.4 vol. % H2O, or 1.6 vol. % NO in the feed compared with the Co3O4 catalyst. The excellent activity of the Co0.6Ti catalyst can be attributed to the higher amount of surface Co3+ derived from the interaction of the Co and Ti oxide in the CoxTi catalysts. Nitrous oxide decomposition: A Co–Ti oxide catalyst with a Co/Ti molar ratio of 0.6 shows high catalytic stability and strong resistance against O2, H2O, and NO for N2O decomposition, which is attributed to the high amount of surface Co3+ based on the interaction between the Co and Ti oxide.