A CHA zeolite supported Ga-oxo cluster for partial oxidation of CH4 at room temperature
A CHA zeolite supported Ga-oxo cluster for partial oxidation of CH4 at room temperature
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DOI：
10.1016/j.cattod.2019.10.035
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发表时间：
2020-08
期刊：
影响因子：
5.3
通讯作者：
Shunsaku Yasumura;M. Huang;Xiaopeng Wu;Chong Liu;Takashi Toyao;Z. Maeno;K. Shimizu
中科院分区：
文献类型：
--
作者：
Shunsaku Yasumura;M. Huang;Xiaopeng Wu;Chong Liu;Takashi Toyao;Z. Maeno;K. Shimizu
在温和条件下活化ch4的催化系统需求量很大。本研究采用还原性固态离子交换法，在CHA沸石中制备了Ga-oxo簇，再进行o2处理。利用x射线吸收精细结构（XAFS）测量证实了Ga-oxo簇的形成。通过从头算热力学分析，建立了合理的星团模型。重要的是，CHA沸石负载的ga -o簇促进ch4的部分氧化，生成吸附的甲醛和甲酸。密度泛函理论（DFT）计算结果表明，Z2[Ga2(O)(OH)2]可能是CH4活化C-H键最活跃的簇。实验和理论结果表明，主基团金属氧簇具有作为CH4转化的活性物质的潜力。
A catalytic system for activation of CH4under mild conditions is in high demand. In this study, Ga-oxo clusters in CHA zeolites were prepared by reductive solid-state ion-exchange followed by O2treatment. Formation of the Ga-oxo clusters was demonstrated using X-ray absorption fine structure (XAFS) measurements. Plausible models of the cluster were developed by using an ab initio thermodynamic analysis. Importantly, the CHA zeolite-supported Ga-oxo clusters promote partial oxidation of CH4to yield adsorbed formaldehyde and formic acid. The results of density functional theory (DFT) calculations, designed to gain information about the mechanism of the process, show that the Z2[Ga2(O)(OH)2] is likely the most active cluster for C–H bond activation of CH4. Observations made in this experimental and theoretical effort demonstrate that main-group metal-oxo clusters have the potential of serving as active species for transformations of CH4.