Catalytic Performance of Gold Supported on Mn, Fe and Ni Doped Ceria in the Preferential Oxidation of CO in H-2-Rich Stream
Catalytic Performance of Gold Supported on Mn, Fe and Ni Doped Ceria in the Preferential Oxidation of CO in H-2-Rich Stream
复制标题
Mn、Fe、Ni掺杂二氧化铈负载金对富氢流中CO优先氧化的催化性能
DOI：
10.3390/catal8100469
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发表时间：
2018
期刊：
影响因子：
3.9
通讯作者：
Wang Jianguo
中科院分区：
文献类型：
--
作者：
Li Shuna;Zhu Huaqing;Qin Zhangfeng;Zhang Yagang;Wang Guofu;Wu Zhiwei;Fan Weibin;Wang Jianguo
氧化铈负载的金属催化剂通常在富氢流中的CO优先氧化（PROX）中表现出高活性，并且用其他金属掺杂氧化铈载体被证明是相当有效的，以进一步提高其催化性能。因此，本文采用改进的水热法合成了一系列Mn、Fe、Ni掺杂的氧化铈材料（CeM，其中M = Mn、Fe、Ni; M/Ce = 1/8）;以掺杂的氧化铈材料（CeM）为载体，采用胶体沉积法制备了多种负载型金催化剂（Au/CeM）。通过N2吸附、XRD、TEM、拉曼光谱、H2-TPR、XPS和XAS等表征手段，详细研究了金属掺杂对金负载氧化铈催化剂在CO PROX中性能的影响。结果表明，Mn、Fe、Ni等金属离子的引入可显著增加氧化铈载体中的氧空位，有利于氧化铈的还原性、金属与载体的相互作用以及金物种的分散。虽然负载在不同掺杂氧化铈上的金催化剂在Au纳米颗粒的尺寸和状态上相似，但在室温下，CO PROX在Au/CeMn、Au/CeFe和Au/CeNi催化剂上的转化率分别为65.6%、93.0%和48.2%，远高于未掺杂的Au/CeO 2催化剂上的33.6%。对于在Au/CeNi催化剂上的CO PROX，CO的转化率在60-130 °C下保持接近100%，对CO2的PROX选择性高于50%。Au/CeNi催化剂的优异性能归因于其大量的氧空位和Ni的引入带来的高还原性。研究结果有助于阐明其他金属掺杂对氧化铈物化性质的影响，进而有助于建立氧化铈负载金催化剂的结构-性能关系，以及开发更好的催化剂用于脱除氢气中的微量CO和生产高纯氢气。
Ceria supported metal catalysts often exhibit high activity in the preferential oxidation (PROX) of CO in H2-rich stream and doping the ceria support with other metals proves to be rather effective in further enhancing their catalytic performance. Therefore, in this work, a series of ceria materials doped with Mn, Fe and Ni (CeM, where M = Mn, Fe and Ni; M/Ce = 1/8) were synthesized by a modified hydrothermal method; with the doped ceria materials (CeM) as the support, various supported gold catalysts (Au/CeM) were prepared by the colloidal deposition method. The influence of metal dopant on the performance of these ceria materials supported with gold catalysts in CO PROX was then investigated in detail with the help of various characterization measures such as N2 sorption, XRD, TEM, Raman spectroscopy, H2-TPR, XPS and XAS. The results indicate that the incorporation of Mn, Fe and Ni metal ions into ceria can remarkably increase the amount of oxygen vacancies in the doped ceria support, which is beneficial for enhancing the reducibility of ceria, the metal-support interaction and the dispersion of gold species. Although the gold catalysts supported on various doped ceria are similar in the size and state of Au nanoparticles, the CO conversions for CO PROX over Au/CeMn, Au/CeFe and Au/CeNi catalysts are 65.6%, 93.0% and 48.2%, respectively, much higher than the value of 33.6% over the undoped Au/CeO2 catalyst at ambient temperature. For CO PROX over the Au/CeNi catalyst, the conversion of CO remains near 100% at 60–130 °C, with a PROX selectivity to CO2 of higher than 50%. The excellent performance of Au/CeNi catalyst can be ascribed to its large amount of oxygen vacancies and high reducibility on account of Ni incorporation. The insight shown in this work helps to clarify the doping effect of other metals on the physicochemical properties of ceria, which is then beneficial to building a structure-performance relation for ceria supported gold catalyst as well as developing a better catalyst for removing trace CO in the hydrogen stream and producing high purity hydrogen.