High-Temperature Selective Oxidation of H2S to Elemental Sulfur on a β-SiC-Supported Cerium Catalyst
High-Temperature Selective Oxidation of H2S to Elemental Sulfur on a β-SiC-Supported Cerium Catalyst
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DOI：
10.1021/acs.iecr.1c01370
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发表时间：
2021-08
影响因子：
4.2
通讯作者：
Xinrui Xu;Ganggang Li;Zheng Wei;Fenglian Zhang;Guoxia Jiang;Jie Cheng;Zhongshen Zhang;Yaxu Zhao;Z. Hao
中科院分区：
文献类型：
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作者：
Xinrui Xu;Ganggang Li;Zheng Wei;Fenglian Zhang;Guoxia Jiang;Jie Cheng;Zhongshen Zhang;Yaxu Zhao;Z. Hao
高温硫化氢选择性催化氧化是一种经济有效的直接处理贫酸气体的方法。本文采用简单的浸渍法制备了β-SiC催化剂负载的Ce，并在较高的温度范围内考察了其对H_2S选择性氧化反应的催化性能。10%CeO2/β-SiC催化剂在300℃时表现出良好的H_2S转化率(93%)和良好的硫选择性(94%)，即使在550℃以下也能分别保持在82%和87%。值得注意的是，该催化剂具有良好的反应稳定性，可在550℃连续反应30h，并可在300~550℃循环运行3次而没有明显失活。这说明β-SiC载体使CeO2粒子具有良好的分散性，从而进一步提高了10%CeO2/β-SiC催化剂的还原性能。此外，催化剂表面丰富的氧空位通过提供大量的表面吸附氧和改善晶格氧的迁移率来促进O2的活化。特别是β-碳化硅载体的高热稳定性在高温反应中起着重要的作用，而β-碳化硅载体与CeO2之间强烈的Ce-O-Si相互作用使催化剂具有良好的抗SO2中毒性能。该工作为稀酸气体的治理提供了一条有前景的途径。
H2S-selective catalytic oxidation at high temperatures is a cost-effective way to directly treat lean acid gas. Herein, cerium supported on a β-SiC catalyst was synthesized by a simple impregnation method, and the catalytic behavior for the H2S-selective oxidation reaction was evaluated at a relatively high-temperature range (300–550 °C). The 10%CeO2/β-SiC catalyst exhibited excellent H2S conversion (93%) and outstanding sulfur selectivity (94%) at 300 °C and could maintain it at 82 and 87%, respectively, even at temperatures up to 550 °C. Remarkably, the catalyst revealed prominent reaction stability, which could proceed consecutively at 550 °C for 30 h and could also run circularly from 300 to 550 °C three times without notable deactivation. This demonstrated that the β-SiC support allowed good dispersion of CeO2particles, which further improved the reducibility of the 10%CeO2/β-SiC catalyst. Furthermore, the abundant oxygen vacancies on the catalyst surface facilitated O2activation by providing a large amount of surface adsorbed oxygen and by improving the lattice oxygen mobility. Particularly, the high thermal stability of the β-SiC support displayed a significant role in high-temperature reactions, and the strong Ce–O–Si interaction between the β-SiC support and the CeO2phase allowed the catalyst a good resistance to SO2poisoning. This work provides a prospective way for the treatment of lean acid gas.