当前位置: X-MOL 学术Matter › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Revealing Molecular Mechanisms in Hierarchical Nanoporous Carbon via Nuclear Magnetic Resonance
Matter ( IF 17.3 ) Pub Date : 2020-10-22 , DOI: 10.1016/j.matt.2020.09.024
Haiyan Mao , Jing Tang , Jun Xu , Yucan Peng , Jun Chen , Bing Wu , Yuanwen Jiang , Kaipeng Hou , Shuo Chen , Jiangyan Wang , Hye Ryoung Lee , David M. Halat , Bing Zhang , Wei Chen , Ariel Z. Plantz , Zhiyi Lu , Yi Cui , Jeffrey A. Reimer

Hierarchical nanoporous carbons (HNC) have been proven to be an effective adsorbent for the adsorption of volatile organic compounds (VOCs) and CO2. However, questions remain regarding the hierarchical structure regulation, the adsorption mechanisms of adsorbate uptake, and interactions within the HNC. We synthesize HNC from wood, using a microwave-induced heating method incorporating K2CO3 activation. Our HNC exhibit Murray's law multiscale structures, prompting a molecular-scale study of adsorbate adsorption via nuclear magnetic resonance (NMR). NMR chemical shifts are consistent with ring-current effects from the adsorbent. Our NMR technique provides a convenient way to quantitate adsorption of adsorbate in HNC. VOC vapor adsorption results show NMR chemical-shift changes with time, suggesting initial adsorption into mesopores, followed by diffusion into micropores. Schroeder's paradox is demonstrated by differences in observed shifts for adsorbed liquid vis-à-vis vapor phase in these HNC. These HNC show high CO2 adsorption capacity, portending applications to carbon capture.



中文翻译:

通过核磁共振揭示分层纳米多孔碳中的分子机理

层级纳米多孔碳(HNC)已被证明是用于吸附挥发性有机化合物(VOC)和CO 2的有效吸附剂但是,关于层次结构的调节,被吸附物吸收的吸附机制以及HNC内部的相互作用,仍然存在疑问。我们使用结合K 2 CO 3的微波加热法从木材合成HNC激活。我们的HNC展示了穆雷定律的多尺度结构,从而促进了通过核磁共振(NMR)进行吸附物吸附的分子尺度研究。NMR化学位移与吸附剂的环流效应一致。我们的NMR技术为定量HNC中吸附物的吸附提供了一种方便的方法。VOC蒸气吸附结果显示NMR化学位移随时间变化,表明最初吸附到中孔中,然后扩散到微孔中。在这些HNC中,吸附液相对于汽相的观察到的位移差异证明了施罗德悖论。这些HNC表现出高的CO 2吸附能力,预示着碳捕集的应用。

更新日期:2020-12-02
down
wechat
bug