Reinforced CO₂ Capture on Amine-Impregnated Organosilica with Double Brush-like Additives Modified

Abstract

Additive introduction based on porous amine-silica hybrid materials is one of the key technologies to enhance the ability of CO2 capture. Hence, we first developed a one-step strategy of directly introducing brush-like cetyltrimethylammonium chloride (CTAC) and bis-(γ-triethoxysilylpropyl)-tetrasulfide (BTES) additives into the silica support to prepare micro-mesoporous organosilica nanoparticles with double brush-like additives modified (MMON-D). Then, the amine-functionalized CO2 adsorbent (MMON-D-50) was obtained via tetraethylenepentamine impregnation. The adsorbent with double additives exhibited a higher CO2 adsorption performance (4.04 mmol/gadsorbent and 0.33 mmol CO2/mmol N under pure CO2 and 25 °C conditions) than that of the adsorbents with none or a single additive. Furthermore, spectra analysis, kinetics, and adsorption heats were performed to clarify the adsorption mechanism of the synergistic action of CTAC and BTES. The results revealed that CTAC as a quaternary ammonium formed on the adsorbent surface can facilitate the formation of carbamic acid. Meanwhile, BTES as a swelling agent endows silica support with a large pore size and inhibits the formation of silylpropyl carbamate to enhance CO2 adsorption performance. This work supplies a novel surface-modified strategy for developing adsorbents with excellent CO2 capture performance, which is of prime importance for both academic interests and practical applications.

Additives enhancing supported amines performance in CO2 capture from air

“…reported that the adsorbent (MMSN‐30/TEPA‐50) with the appropriate amount of brush‐like cetyltrimethylammonium chloride (CTAC) exhibited higher CO 2 adsorption capacities (3.68 mmol g −1 under simulated dry air conditions) than that of the adsorbents with none or fewer additives, 45 which is the most significant enhancement in low CO 2 concentration range. Further, the researchers added bis‐(γ‐triethoxysilylpropyl)‐tetrasulfide to the CTAC‐modified adsorbents, which led to an even greater increase in adsorption values under flue gas conditions (75°C, 15 vol.%) 46 . In another study, PEG400‐modified PEI‐fumed silica showed the most substantial enhancement, reaching 71.8% in the pure CO 2 case.…”

“…Further, the researchers added bis-(γ-triethoxysilylpropyl)tetrasulfide to the CTAC-modified adsorbents, which led to an even greater increase in adsorption values under flue gas conditions (75 • C, 15 vol.%). 46 In another study, PEG400-modified PEI-fumed silica showed the most substantial enhancement, reaching 71.8% in the pure CO 2 case. This improvement might be attributed to the beneficial effect of the hydroxyl group.…”

“…44 Pre-synthesis by retaining the templating agent is another feasible way to incorporate additives, which is usually achieved by avoiding calcination at the end of substrate production. [45][46][47][48] C in pure CO 2 . 49 and amine, thereby improving the adsorptive capacity of this pure CO 2 adsorption system.…”

“…Pre‐synthesis by retaining the templating agent is another feasible way to incorporate additives, which is usually achieved by avoiding calcination at the end of substrate production 45–48 . Han et al.…”

Investigation on Regulating Porous Polymers with Suitable Porosities and/or N-Doping for Enhanced CO2 Capture

“…All HCLPs showed similar type I N 2 adsorption−desorption isotherms (Figure 4a) with high N 2 adsorption at low relative pressures (P/P 0 < 0.001), indicating the substantial presence of micropores. 34,35 Steep rises at high relative pressures (P/P 0 > 0.9) of N 2 adsorption−desorption isotherms suggested the existence of the mesopores and/or macropores in HCLPs resulting from interparticle porosity or voids. 36,37 Significant hysteresis in the desorption branch for HCLPs was in agreement with elastic deformations or swelling on account of gas sorption.…”