Zeolite Nanocrystals Embedded in Microcellular Carbon Foam as a High‐Performance CO₂ Capture Adsorbent with Energy‐Saving Regeneration Properties

Abstract

Here, the facile synthesis of four‐length‐scaled (ultramicro‐micro‐meso‐macroporous) hierarchically structured porous carbon nanocomposite by an emulsion‐template strategy is reported. This previously unreported combination of zeolite nanocrystals embedded in the walls of microcellular carbon foams gives unique textural and structural properties, which result in their excellent ability to selectively capture CO2 owing to the presence of ultra‐micropores. The zeolite–microcellular carbon foam synergism delivers an adsorbent with a significantly enhanced CO2 capture capacity of up to 5 mmol g−1, CO2/N2 selectivity of up to 80, and an outstanding multi‐cycle capture performance under humid conditions (70 % performance retention after 30 regeneration cycles). More impressively, the electrically conductive carbon framework enables Joule heating and cooling, and thus fast and energy‐efficient regeneration is possible, with an estimated energy consumption of only about 12 kWh.

Modulating the porosity of carbons for improved adsorption of hydrogen, carbon dioxide, and methane: a review

“…This can be achieved by forming composites with some other material, however by definition the composite's porosity is then a result of the structures of both the ZTC and the other material. [359][360] On the other hand, Choi et al found that through thermal treatment of ZTCs, a contraction in the width of micropores is produced, associated with loss of structural hydrogen, improved packing density and decreased gravimetric porosity. Consequently, volumetric methane capacity (65 bar, 25 o C) was improved by 7% from 164 to 176 cm 3 STP cm -3 on a ZTC synthesised using BEA as a template, following heat treatment at 600 o C. 14 Other thermal, chemical and pressure treatments can lead to greater improvements in porosity and therefore improved gas uptakes.…”

Fundamentals and Design‐Led Synthesis of Emulsion‐Templated Porous Materials for Environmental Applications

“…This produced a zeolite-embedded carbon material with interconnected four-length-scaled ultramicro-, micro-, meso-, and macropores, and a surface area of 362 m 2 g −1 . [250] Deshmukh et al introduced TEOS in the oil phase (toluene) of an O/W HIPE and fabricated a PAM-silica hybrid polyHIPE. Porous silica-carbon composite was obtained after pyrolyzing at 800-1000 °C under Ar.…”

“…18 cm 3 g −1 ; conductivity: up to 300 S m −1 ; micro-/mesopore volume: 0.313 cm 3 g −1 [249] Zeolite-embedded carbon zeolite@PAM polyHIPE prepared Thermally treated at 450 °C in air and then carbonized at 900 °C under Ar 3D-interconnected hierarchical ultramicro-, micro-, meso-, and macro-pore system Surface area: 362 m 2 g −1 [250] (Continued) Very low density: 1 mg cm −3 Properties tunable based on preparation conditions.…”

“…This enabled a fast and energy-efficient regeneration of zeolite@carboHIPEs as adsorbents. [250] Silica-P(St-co-DVB) polyHIPEs were fabricated by using the acidified cotton as a stabilizer. These polyHIPEs offered good mechanical stability, high porosity, high diffusivity, and strong affinity for the particulate matter.…”

“…The ultramicropores from zeolite combined with highly interconnected macro‐ and mesopores from the carbon matrix helped to achieve a CO 2 uptake capacity of 5 mmol g −1 , CO 2 /N 2 selectivity of up to 80, and recyclability under humid conditions (50% humidity, 70% performance retention after 30 regeneration cycles). [ 250 ] This adsorbent was regenerated via an electric swing adsorption method. It was therefore essential to utilize the electrically conductive carbon matrix (2.2 S m −1 ) to generate efficient Joule‐heating under the applied voltages.…”