Qin, Haijian, Yang, Zelong, Xia, Qing, PeifeiYao, Zheng, Chunzhi, Lin, Guangpin, Ye, Zhaolian, Zhao, Songjian, and Yang, Fengli
• Co 3 O 4 loaded on different forms of Ta 2 O 5 (amorphous, mesoporous, crystalline, crystalline mesoporous) are used for CO oxidation. • Crystalline mesoporous structure of Co/Ta-cm could promote CO conversion. • Co/Ta-cm exhibited the good CO conversion, and the temperature of 90% CO conversion was approximately 130 ℃ at the high space velocity of 780,000 h−1. Because the combination of Co and common support (Al, Ti, et al.) usually shows poor catalytic activity, tantalum has been introduced for CO conversion as a novel carrier due to the excellent performance. In this work, Co 3 O 4 was loaded on four forms of tantalum support (amorphous, mesoporous, crystalline and crystalline mesoporous, abbreviated as Co/Ta-am, Co/Ta-me, Co/Ta-cry and Co/Ta-cm, respectively). And among these four states, Co/Ta-cm presents the highest CO conversion rate. The temperature of 90% CO conversion rate of Co/Ta-cm is approximately 130 ℃ at the high space velocity of 780,000 h−1, which is 70%, 82% and 88% higher than that of Co/Ta-cry, Co/Ta-me and Co/Ta-am, respectively. Moreover, the characteristics of the catalyst have been studied by XRD, SEM, BET, TGA, and H 2 -TPR, and the results reveal that Co/Ta-cm has the excellent crystallinity and stability, and the morphology is regular. X-ray photon spectroscopy and in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTs) have been performed to investigate the reaction mechanism, which indicates that Co3+ is the active component and lattice oxygen plays a critical role in CO oxidation. [ABSTRACT FROM AUTHOR]