Cage effects control the mechanism of methane hydroxylation in zeolites

doi:10.1126/science.abd5803

GSTDTAP > 气候变化

DOI	10.1126/science.abd5803
	Cage effects control the mechanism of methane hydroxylation in zeolites
	Benjamin E. R. Snyder; Max L. Bols; Hannah M. Rhoda; Dieter Plessers; Robert A. Schoonheydt; Bert F. Sels; Edward I. Solomon
	2021-07-16
发表期刊	Science
出版年	2021
英文摘要	Zeolite catalysis could potentially offer a more direct route from methane to methanol. However, current catalysts tend to deactivate too quickly for practical use. Snyder et al. investigated the deactivation mechanism using Mössbauer and Raman spectroscopy and accompanying simulations (see the Perspective by Scott). Their results suggest that in zeolites with large apertures, after iron active sites strip hydrogen from methane, the resulting methyl radicals can leak away and deactivate other iron centers. Zeolites with tighter apertures can keep the radicals nearby longer, favoring the formation of methanol. Science , abd5803, this issue p. [327][1]; see also abj4734, p. [277][2] Catalytic conversion of methane to methanol remains an economically tantalizing but fundamentally challenging goal. Current technologies based on zeolites deactivate too rapidly for practical application. We found that similar active sites hosted in different zeolite lattices can exhibit markedly different reactivity with methane, depending on the size of the zeolite pore apertures. Whereas zeolite with large pore apertures deactivates completely after a single turnover, 40% of active sites in zeolite with small pore apertures are regenerated, enabling a catalytic cycle. Detailed spectroscopic characterization of reaction intermediates and density functional theory calculations show that hindered diffusion through small pore apertures disfavors premature release of CH3 radicals from the active site after C-H activation, thereby promoting radical recombination to form methanol rather than deactivated Fe-OCH3 centers elsewhere in the lattice. [1]: /lookup/doi/10.1126/science.abd5803 [2]: /lookup/doi/10.1126/science.abj4734
领域	气候变化 ; 资源环境
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引用统计
文献类型	期刊论文
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/334389
专题	气候变化资源环境科学
推荐引用方式 GB/T 7714	Benjamin E. R. Snyder,Max L. Bols,Hannah M. Rhoda,et al. Cage effects control the mechanism of methane hydroxylation in zeolites[J]. Science,2021.
APA	Benjamin E. R. Snyder.,Max L. Bols.,Hannah M. Rhoda.,Dieter Plessers.,Robert A. Schoonheydt.,...&Edward I. Solomon.(2021).Cage effects control the mechanism of methane hydroxylation in zeolites.Science.
MLA	Benjamin E. R. Snyder,et al."Cage effects control the mechanism of methane hydroxylation in zeolites".Science (2021).