Studies on Cu-Containing MFI Zeolites by H_2-TPR and O_2-TPD
Studies on Cu-Containing MFI Zeolites by H_2-TPR and O_2-TPD
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DOI：
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发表时间：
2001
影响因子：
16.5
通讯作者：
Guan Naijia
中科院分区：
文献类型：
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作者：
Guan Naijia
采用H2程序升温还原（H2 TPR）和O2程序升温脱附（O2 TPD）方法对不同金属离子交换的ZSM-5分子筛进行了研究。用H2 TPR对纯Cu ZSM 5和原位合成Cu ZSM 5/堇青石整体式催化剂进行了表征，比较了Cu ZSM 5和原位合成Cu ZSM 5/堇青石整体式催化剂上铜离子的氧化态。结果表明，Cu ZSM 5催化剂的储氧性能优于Co ZSM 5和Fe ZSM 5。NO分解催化剂的活性与该性质密切相关。铜离子是反应的活性中心。Ag和Ce助剂的加入降低了O2的脱附温度，表明Ag和Ce助剂的加入有利于O2从催化剂表面脱附。Cu ZSM 5/堇青石整体式催化剂上Cu的存在状态与纯Cu ZSM 5上不同。整体式样品上的Cu+物种较少，但比纯Cu ZSM 5上的更稳定。
Different metal ion exchanged ZSM 5 zeolites were investigated by means of H 2 temperature programmed reduction (H 2 TPR) and O 2 temperature programmed desorption (O 2 TPD). Pure Cu ZSM 5 and in situ synthesized Cu ZSM 5/cordierite monolithic catalysts were also characterized by H 2 TPR in order to compare the oxidation states of copper ions on them. The results show that the Cu ZSM 5 catalyst has superior oxygen storage capacity than the Co ZSM 5 and Fe ZSM 5. The catalyst activity for NO decomposition is closely related to this property. Copper ions are the active sites for the reaction. The addition of Ag and Ce as promoters decreases the temperature of O 2 desorption, which indicates that adding Ag and Ce favors the O 2 desorption from the catalyst surface. The state of Cu on the Cu ZSM 5/cordierite monolithic catalyst is different from that on the pure Cu ZSM 5. Less Cu + species is found on the monolithic sample but it is more stable than that on the pure Cu ZSM 5.