Dramatic Enhancement of CO₂ Uptake by Poly(ethyleneimine) Using Zirconosilicate Supports

Abstract

The CO(2) adsorption characteristics of prototypical poly(ethyleneimine)/silica composite adsorbents can be drastically enhanced by altering the acid/base properties of the oxide support via incorporation of Zr into the silica support. Introduction of an optimal amount of Zr resulted in a significant improvement in the CO(2) capacity and amine efficiency under dilute (simulated flue gas) and ultradilute (simulated ambient air) conditions. Adsorption experiments combined with detailed characterization by thermogravimetric analysis, temperature-programmed desorption, and in situ FT-IR spectroscopy clearly demonstrate a stabilizing effect of amphoteric Zr sites that enhances the adsorbent capacity, regenerability, and stability over continued recycling. It is suggested that the important role of the surface properties of the oxide support in these polymer/oxide composite adsorbents has been largely overlooked and that the properties may be even further enhanced in the future by tuning the acid/base properties of the support.

Vapor-enhanced CO2 adsorption mechanism of composite PEI@ZIF-8 modified by polyethyleneimine for CO2/N2 separation

“…Here, the well reserved ZIF-8 structure after loading PEI suggested an excellent alkali-resistance property of ZIF-8. Moreover, it was noticed that the intensity of the characteristic peaks of ZIF-8 decreased with PEI loading, which may be ascribed to a fairly strong binding of PEI to ZIF-8, more specifically, the Zn sites on ZIF-8 [36]. …”

Effect of Chain Topology of Polyethylenimine on Physisorption and Chemisorption of Carbon Dioxide

“…[21] High-efficiency sorbents have been developed based on PEI-functionalized mesoporousmaterials. [22][23][24][25][26] CO 2 capture with amine-based absorbents involves chemisorptiona nd physisorption. In general, absorption of CO 2 on the aminem ediumf irstly occurs as physisorption in which aC O 2 molecule binds with the mediums urface by van der Waals and electrostatic interactions.…”

Modification of acid sites in ZSM-5 by ion-exchange: An in-situ FTIR study

“…[65][66][67][68][69][70][71][72] For example, Kuwahara et al designed a new class of heterogeneous catalytic systems utilizing this effect: cation-π interactions (π from potential reactive molecules) in microporous titanosilicate molecular sieves for cyclohexene epoxidation [39]. Possibly the heavier alkali metal cations (K + , Rb + , and Cs + ) have an increased interaction with the cyclohexene molecules as a result of a weak cation-π interaction, which results in an enhancement of their catalytic activity and selectivity for epoxidation.…”