CAS Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, Fujian 361021, China; CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, Fujian 361021, China.
Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen, Fujian 361005, China; Fujian Key Laboratory of Advanced Materials, Xiamen, Fujian 361005, China.
J Colloid Interface Sci. 2018 Nov 15;530:412-423. doi: 10.1016/j.jcis.2018.06.094. Epub 2018 Jun 30.
Massive amount of CO emission, which could cause climate change, has been recognized as a serious environmental issue. Chemical adsorption is generally considered as a promising technology for CO capture in low CO partial pressure. Physical properties and chemical components of the adsorbent are important to CO adsorption performance. To address structure limitation and complicated preparation process of the conventional adsorbent, herein, we reported a rapid and simple route to synthesis amine-modified silica aerogel monolith by co-precursor sol-gel method. Microstructure and the surface functional groups of the amine-modified silica aerogel could be easily manipulated. The products were characterized by SEM, XPS, NMR, in situ DRIFT and CNS elemental analyzer. The amine-modified silica aerogel exhibited good physical properties and demonstrated excellent CO adsorption performance. The density, porosity and BJH pore volume of the amine-modified silica aerogel were 0.12 g/cm, 94.5% and 2.39 cm/g, respectively. The maximum static and dynamic adsorption capacities of CO on the amine-modified silica aerogel were 2.2 mmol/g and 5.59 mmol/g under anhydrous and humid mixed gas conditions, respectively. The as-prepared aerogel also showed good cyclic ability for CO adsorption and desorption. The CO adsorption on the amine-modified silica aerogel is by the formation of carbamate through a two-step zwitterion mechanism. This easily prepared amine-modified silica aerogel could be a promising adsorbent for CO capture.
大量的 CO 排放会导致气候变化，已被认为是一个严重的环境问题。化学吸附通常被认为是一种在低 CO 分压下捕获 CO 的有前途的技术。吸附剂的物理性质和化学组成对 CO 的吸附性能很重要。为了解决传统吸附剂的结构限制和复杂的制备工艺问题，我们在此报告了一种通过共前体溶胶-凝胶法快速简便地合成胺改性硅胶气凝胶整体的方法。胺改性硅胶气凝胶的微观结构和表面官能团可以很容易地进行调控。通过 SEM、XPS、NMR、原位 DRIFT 和 CNS 元素分析仪对产物进行了表征。胺改性硅胶气凝胶具有良好的物理性能，并表现出优异的 CO 吸附性能。胺改性硅胶气凝胶的密度、孔隙率和 BJH 孔体积分别为 0.12 g/cm、94.5%和 2.39 cm/g。在无水和湿混合气体条件下，胺改性硅胶气凝胶对 CO 的最大静态和动态吸附容量分别为 2.2 mmol/g 和 5.59 mmol/g。所制备的气凝胶对 CO 的吸附和解吸也表现出良好的循环能力。胺改性硅胶气凝胶对 CO 的吸附是通过两步两性离子机理形成氨基甲酸酯来实现的。这种易于制备的胺改性硅胶气凝胶可能是一种很有前途的 CO 捕获吸附剂。
