Development of Ultramicropore-Mesopore Interconnected Pore Architectures for Boosting Carbon Dioxide Capture at Low Partial Pressure

Abstract

The physical adsorption of carbon dioxide (CO₂) using porous solid adsorbent is greatly hindered by high temperature and low pressure, resulting in a decrease in capture performance in terms of capacity, selectivity and kinetics. Here we report an effective synthesis of 3D hierarchical porous carbon with ultramicropore-mesopore interconnected pore architectures that are able to boost the CO₂ adsorption at elevated temperature and low partial pressure. This unique pore structures is benefit from the uniform introduction of a combination of alkali metals (Li, Na, K) and other metals (Mg, Ca, Zn) in the resin precursor. Specifically, the employed dual metal in-situ activation method allows generation of extensive mesopores with pore size in the range of 3-5 and 7-9 nm without sacrificing distribution of ultramicropore. These properties result in an enhanced dynamic CO₂ capacities from 1.36 to 1.54 mmol/g (40 °C and 0.15 bar), higher CO₂/N₂ selectivities from 73 to 85 as well as advanced mass transport kinetics. This work paves the way for the development of high performance CO₂ adsorbent at low partial pressure and provides a strategy to prepare interconnected pore architectures for a variety of potential adsorption application.

Keywords: CO2 Capture, adsorption, pore structure, ultramicropore, mesopore