Influence of Ce/Nb Molar Ratios on Oxygen-Rich Ce.sub.xNb.sub.1-xO.sub.4+[delta] Materials for Catalytic Combustion of VOCs in the Process of Polyether Polyol Synthesis

• Published in: Catalysis letters 2022-02, Vol.152 (2), p.523
• Main Authors: Yang, Peng, Jin, Yinying, Zhang, Xiuwen, Qi, Chenze, Shi, Juan, Tang, Jiang, Luo, Hong
• Format: Article
• Language: English
• Subjects: Air pollution; Combustion; Oxides; Polyols; Volatile organic compounds
• ISSN: 1011-372X
• DOI: 10.1007/s10562-021-03652-2

Catalytic combustion is an efficient and economical technique to deal with the air pollution of diluted volatile organic compounds (VOCs). In this work, oxygen-rich CeO.sub.2-Nb.sub.2O.sub.5 mixed oxides (Ce.sub.xNb.sub.1-xO.sub.4+[delta]) with varied Ce/Nb molar ratios in the bulk synthesized by modified sol-gel method were investigated for complete catalytic combustion of VOCs as exemplified by monochlorobenzene and toluene. To reveal the structure-function relationship of these materials, comprehensive catalytic performance evaluation and characterizations were performed, which showed that the 4Ce1Nb catalyst (CeO.sub.2-Nb.sub.2O.sub.5 with Ce/Nb molar ratio of 4:1) displayed superb apparent catalytic activity. Complete oxidation could be accomplished below 300 °C, which was significantly lower than that of single-component CeO.sub.2 or Nb.sub.2O.sub.5, as well as some other types of V and Cr based mixed oxide catalysts. Moreover, the apparent catalytic activity of 4Ce1Nb could be maintained for at least 100 h at 280 °C with high selectivity to the formation of HCl and CO.sub.2. The improved catalytic performance of 4Ce1Nb could be ascribed to the formation of oxygen-rich Ce.sub.xNb.sub.1-xO.sub.4+[delta] mixed oxides with high dispersion of Ce and Nb species into each other, the strong interaction of Ce-O-Nb, an abundance of active oxygen species, high specific surface area and mesoporous structure.