Understanding the correlation between calcination temperature and performance in low‐temperature methanation over Ni‐Zr/Al2O3 catalysts. (11th February 2020)

• Record Type: Journal Article
• Authors: Zhang, Junfeng; Zhang, Meng; Chen, Shuyao; Zhou, Zeling; Zheng, Kaiwen; Bai, Yunxing; Tan, Yisheng; Han, Yizhuo
• Is Part Of: Canadian journal of chemical engineering. Volume 98:Number 7(2020)
• Page Start: 1525
• Page End: 1533
• Publication Date: 2020-02-11
• Subjects: calcination temperature -- low‐temperature methanation -- Ni‐Zr/γ‐Al2O3 -- stability; Chemical engineering -- Periodicals; Technology -- Periodicals; 660.05
• DOI: 10.1002/cjce.23709
• Languages: English
• ISSNs: 0008-4034

Abstract

Abstract: Low‐temperature methanation of CO in the continuous stirred tank reactor (CSTR) over Zr doped Ni/Al2 O3 catalyst calcined at different temperatures (673, 723, and 823 K) was investigated. XRD, TPR, XPS, ICP, SEM, and S ‐TPR techniques were employed to characterize the fresh and spent catalysts. Based on the characterization results, it was found that low‐temperature (673 K) calcination could effectively prohibit the formation of NiAl2 O4 spinel, thereby resulting in more reducible NiO particles, which were the essential precursor of methanation active sites over the catalyst surface. Thus, the highest CO conversion of 93.6% was achieved over the 25N3ZA‐673 catalyst. In addition, the deactivation rate of 25N3ZA‐673 was relatively slow in comparison to 25N3ZA‐823 due to the presence of more reducible NiO. The formed nickel carbonyl species (Ni[CO]x ), which quickly decomposed at a higher reaction temperature, was closely related to the catalyst deactivation. Therefore, 25N3ZA‐673 possessed much better stability at 593 K than that at 553 K. Abstract : Low‐temperature calcination (673 K) to the Zr‐doped Ni/γ‐Al2 O3 catalyst (25N3ZA) could effectively prohibit the formation of NiAl2 O4 spinel and result in more reducible NiO particles, which were essential precursors with high activity and methanation stability.