New Perspectives for Evaluating the Mass Transport in Porous Catalysts and Unfolding Macro- and Microkinetics.
New Perspectives for Evaluating the Mass Transport in Porous Catalysts and Unfolding Macro- and Microkinetics.
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评估多孔催化剂和展开宏观和微动力学的大规模运输的新观点。
DOI：
10.1007/s10562-022-04218-6
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发表时间：
2023
影响因子：
2.8
通讯作者：
中科院分区：
文献类型：
--
作者：
在这篇文章中，我们揭示了新出现的观点来表征和理解气相金属催化剂孔中扩散传质和表面催化过程的相互作用。作为一个案例研究，纳米多孔金，作为一个有趣的例子，表现出明确的孔结构和高活性的全部和部分氧化反应被认为是。PFG NMR（脉冲场梯度核磁共振）测量允许在这里的材料内的气体扩散率的定量评估。STEM（扫描透射电子显微镜）断层扫描进一步提供了对孔隙系统结构细节的额外见解，有助于判断其哪些特征对减缓质量传输最具决定性。基于关于多孔催化剂内部的扩散系数的定量知识，可以从测量的反应动力学中解开传质贡献，并确定潜在的催化表面反应的动力学速率常数。此外，可以预测催化剂的改进的有效性，即，优化转化率。这种方法将在低温CO氧化的例子中讨论，在30 °C下由npAu有效催化。案例研究将揭示，新型多孔材料表现出明确的微观和介观特征和足够的催化活性，与现代技术相结合，以评估扩散运输，提供有趣的新的机会，为催化过程的整体理解。
In this article we shed light on newly emerging perspectives to characterize and understand the interplay of diffusive mass transport and surface catalytic processes in pores of gas phase metal catalysts. As a case study, nanoporous gold, as an interesting example exhibiting a well-defined pore structure and a high activity for total and partial oxidation reactions is considered. PFG NMR (pulsed field gradient nuclear magnetic resonance) measurements allowed here for a quantitative evaluation of gas diffusivities within the material. STEM (scanning transmission electron microscopy) tomography furthermore provided additional insight into the structural details of the pore system, helping to judge which of its features are most decisive for slowing down mass transport. Based on the quantitative knowledge about the diffusion coefficients inside a porous catalyst, it becomes possible to disentangle mass transport contributions form the measured reaction kinetics and to determine the kinetic rate constant of the underlying catalytic surface reaction. In addition, predictions can be made for an improved effectiveness of the catalyst, i.e., optimized conversion rates. This approach will be discussed at the example of low-temperature CO oxidation, efficiently catalysed by npAu at 30 °C. The case study shall reveal that novel porous materials exhibiting well-defined micro- and mesoscopic features and sufficient catalytic activity, in combination with modern techniques to evaluate diffusive transport, offer interesting new opportunities for an integral understanding of catalytic processes.
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影响因子：
15
作者：
ADKINS, H;BILLICA, HR
通讯作者：
BILLICA, HR
影响因子：
1.5
作者：
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3.6
作者：
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Campbell, Charles T.
影响因子：
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通讯作者：
Baeumer, Marcus
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作者：
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通讯作者：
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