Enhanced CO₂ Adsorption over Polymeric Amines Supported on Heteroatom‐Incorporated SBA‐15 Silica: Impact of Heteroatom Type and Loading on Sorbent Structure and Adsorption Performance

Abstract

Silica supported amine materials are promising compositions that can be used to effectively remove CO(2) from large stationary sources, such as flue gas generated from coal-fired power plants (ca. 10 % CO(2)) and potentially from ambient air (ca. 400 ppm CO(2)). The CO(2) adsorption characteristics of prototypical poly(ethyleneimine)-silica composite adsorbents can be significantly enhanced by altering the acid/base properties of the silica support by heteroatom incorporation into the silica matrix. In this study, an array of poly(ethyleneimine)-impregnated mesoporous silica SBA-15 materials containing heteroatoms (Al, Ti, Zr, and Ce) in their silica matrices are prepared and examined in adsorption experiments under conditions simulating flue gas (10 % CO(2) in Ar) and ambient air (400 ppm CO(2) in Ar) to assess the effects of heteroatom incorporation on the CO(2) adsorption properties. The structure of the composite adsorbents, including local information concerning the state of the incorporated heteroatoms and the overall surface properties of the silicate supports, are investigated in detail to draw a relationship between the adsorbent structure and CO(2) adsorption/desorption performance. The CO(2) adsorption/desorption kinetics are assessed by thermogravimetric analysis and in situ FT-IR measurements. These combined results, coupled with data on adsorbent regenerability, demonstrate a stabilizing effect of the heteroatoms on the poly(ethyleneimine), enhancing adsorbent capacity, adsorption kinetics, regenerability, and stability of the supported aminopolymers over continued cycling. It is suggested that the CO(2) adsorption performance of silica-aminopolymer composites may be further enhanced in the future by more precisely tuning the acid/base properties of the support.

Reaction-dependent heteroatom modification of acid–base catalytic cooperativity in aminosilica materials

“…Pluronic P123 block copolymer (EO 20 All SBA-15 materials were prepared according to previous reports [18,19,37,[49][50][51][52][53][54][55]. The details of the synthetic procedures are in the Supporting Information.…”

Polyethyleneimine functionalised nanocarbons for the efficient adsorption ofcarbon dioxide with a low temperature of regeneration

“…[10] Efforts have been made to improve on the traditional amine system by using ionic liquids, [11] as well as making solid supported amines. [12][13][14][15][16][17] However, there is no significant decrease in the desorption temperature of the CO 2 . We have recently reported that when polyethyleneimine (PEI, I) was covalently bonded to single-walled carbon nanotubes (SWNTs) the CO 2 uptake was enhanced as compared to the polymer itself.…”

Development of micro–mesoporous composite material of the ZSM-12/MCM-41 type for the CO2 adsorption

“…Composite materials that combine the zeolitic microporosity with the mesoporosity in amorphous phase of M41S family have attracted special attention due to potential properties and applications in adsorption and catalysis [3]. These properties are not related to the mesoporous and zeolite individual phase characteristics, but with the final assembly and synergy that is consequently formed between the two structures [4].…”