Department of Chemistry, Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Ontario, K1N 6N5 Canada.
J Am Chem Soc. 2012 Aug 22;134(33):13834-42. doi: 10.1021/ja304888a. Epub 2012 Aug 9.
A comprehensive study was conducted to investigate the stability of a wide variety of mesoporous silica-supported amine-containing adsorbents in the presence of carbon dioxide under dry conditions. CO(2)-induced degradation of grafted primary and secondary monoamines (pMono, sMono), diamines with one primary and one secondary amines (Diamine) and triamine with one primary and two secondary amines (TRI) as well as different impregnated polyamines such as branched and linear polyethylenimine (BPEI and LPEI) and polyallylamine (PALL) was investigated using extensive CO(2) adsorption-desorption cycling as well as diffuse reflectance infrared Fourier transform (DRIFT) and (13)C CP MAS NMR measurements. Except for sMono, all other supported amines underwent significant deactivation in the presence of dry CO(2) under mild conditions. In all cases, the decrease in CO(2) uptake was associated with the formation of urea linkages at the expense of amine groups. The urea-containing species were identified, and the deactivation pathways were delineated.
进行了一项全面的研究，以调查在干燥条件下存在二氧化碳的情况下，各种负载胺的介孔硅基吸附剂的稳定性。使用广泛的 CO(2)吸附-解吸循环以及漫反射红外傅里叶变换 (DRIFT) 和 (13)C CP MAS NMR 测量，研究了 CO(2)诱导接枝伯胺和仲胺（pMono、sMono）、一个伯胺和一个仲胺的二胺（Diamine）以及一个伯胺和两个仲胺的三胺（TRI）以及不同浸渍的多胺如支化和线性聚乙烯亚胺（BPEI 和 LPEI）和聚烯丙胺（PALL）的降解。除了 sMono，所有其他负载的胺在温和条件下存在干燥的 CO(2)时都会发生明显的失活。在所有情况下，CO(2)吸收的减少都与尿素键的形成有关，这是胺基团的代价。鉴定了含脲的物质，并描绘了失活途径。
