Development of poplar wood and metal-organic frameworks derived ZIF-8@Porous carbon composites for carbon dioxide adsorption

Abstract

Metal-organic frameworks (MOFs) derived porous carbons have been demonstrated to have dramatic performance in CO2 adsorption. Herein, ZIF-8 was initially synthesized in the pores of Chinese white poplar to prepare composites, and then the composites were carbonized into ZIF-8@Poplar porous carbon for CO2 uptake. The structure and physical-chemical properties of the prepared material were investigated. The results showed that when the molar ratio of metal clusters to organic ligands was 1:4, the synthesized ZIF-8 had small particle size around 150–200 nm and was resistant to 973 K, this confirmed the feasibility for composite of ZIF-8@wood. ZIF-8 was successfully synthesized in situ inside of wood, it suspected combining with wood through hydrogen bonding and electrostatic interactions, and its content in wood was 12.76%. The prepared ZIF-8@Poplar porous carbon was an amorphous carbon with BET surface area of 233.772 m2/g, pore volume of 0.177 cm3/g and the average pore size of 3.024 nm. It had CO2 capacity of 1.33 mmol/g at 298 K at 1 bar with lower N content (based on XPS patterns), the CO2 adsorption was conducted from its abundant micropores, which is corroborated by the heat of CO2 adsorption (34.53 kJ/mol) calculated based on Clausius-Clapeyron equation. Based on Ideal Adsorbed Solution Theory (IAST), it has a good adsorption selectivity of CO2 over N2 on a gas mixture containing 10% CO2 and 90% N2. In summary, in situ synthesis and co-carbonization provide a strategy for the synthesis of MOFs@wood-derived hard porous carbon for superior CO2 uptake in industrial applications.