Revealing the Synergistic Effects of Rh and Substituted La2B2O7 (B = Zr or Ti) for Preserving the Reactivity of Catalyst in Dry Reforming of Methane
Revealing the Synergistic Effects of Rh and Substituted La2B2O7 (B = Zr or Ti) for Preserving the Reactivity of Catalyst in Dry Reforming of Methane
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DOI：
10.1021/acscatal.8b03319
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发表时间：
2018-12
期刊：
影响因子：
12.9
通讯作者：
Juan Wu;L. Qiao;Zhangfeng Zhou;G. Cui;Shanshan Zong;Dong Xu;Run‐Ping Ye;Ruiping Chen;R. Si-R.
中科院分区：
文献类型：
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作者：
Juan Wu;L. Qiao;Zhangfeng Zhou;G. Cui;Shanshan Zong;Dong Xu;Run‐Ping Ye;Ruiping Chen;R. Si-R.
合成了Rh取代的La 2B 2 O 7（B = Zr或Ti）复合氧化物，并将其应用于甲烷干重整（DRM）反应。XRD、拉曼、UV-vis漫反射、HRTEM、HAADF-STEM、原位DRIFTS、XAFS XPS、TPR等表征和DRM反应测试表明，La_2B_2 O_7（B = Zr或Ti）的取代度和催化性能取决于La_2B_2 O_7的组成。结果表明，在致密的Rh-LZO上，几乎所有的Rh物种都取代了Zr，部分Rh取代了Ti，其余的以Rh_2O_3的形式存在于疏松的Rh-LTO表面。CH 4在Rh-La 2 Zr 2 O 7上容易解离，但由于中间碳的快速沉积而难以继续解离，只有提供足够的活性O* 才能解决中间碳的沉积问题。另一方面，钛掺杂的La 2 Ti 2 O 7通过金属-载体界面赋予负载Rh独特的结构和电荷效应，导致Rh 0和Rhδ+共存，在800 °C的DRM过程中协同作用。
Rh substituted-La2B2O7 (B = Zr or Ti) composite oxides were synthesized and applied in the dry reforming of methane (DRM) reaction. The characterizations of XRD, Raman, UV–vis diffuse reflectance, HRTEM, HAADF-STEM, in situ DRIFTS, XAFS XPS, TPR and the tests of DRM reaction have shown that the degree of substitution and the catalytic performance depend on the composition of La2B2O7 (B = Zr or Ti). It is found that almost all Rh species substituted Zr over the compact Rh-LZO while a part of Rh substituted Ti, and the rest existed in the form of Rh2O3 on the surface over the loose Rh-LTO. CH4 was prone to dissociate on Rh–La2Zr2O7 but hard to continue owing to the quickly depositing of intermediate carbon, which would not be resolved unless enough active O* was furnished. On the other hand, titanium-doped La2Ti2O7 conferred unique structural and charge effects to supported Rh through the metal–support interface, leading to the coexistence of Rh0 and Rhδ+ which performed synergistically during DRM at 800 °C...