Strong Foam-like Composites from Highly Mesoporous Wood and Metal-Organic Frameworks for Efficient CO2 Capture

Mechanical stability and multicycle durability are essential for emerging solid sorbents to maintain an efficient CO2 adsorption capacity and reduce cost. In this work, a strong foam-like composite is developed as a CO2 sorbent by the in situ growth of thermally stable and microporous metal-organic frameworks (MOFs) in a mesoporous cellulose template derived from balsa wood, which is delignified by using sodium chlorite and further functionalized by 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-mediated oxidation. The surface carboxyl groups in the TEMPO-oxidized wood template (TO-wood) facilitate the coordination of the cellulose network with multivalent metal ions and thus enable the nucleation and in situ growth of MOFs including copper benzene-1,3,5-tricarboxylate [Cu-3(BTC)2], zinc 2-methylimidazolate, and aluminum benzene1,3,5-tricarboxylate. The TO-wood/Cu-3(BTC)(2) composite shows a high specific surface area of 471 m(2) g(-1) and a high CO2 adsorption capacity of 1.46 mmol g(-1) at 25 degrees C and atmospheric pressure. It also demonstrates high durability during the temperature swing cyclic CO2 adsorption/desorption test. In addition, the TO-wood/Cu-3(BTC)(2) composite is lightweight but exceptionally strong with a specific elastic modulus of 3034 kN m kg(-1) and a specific yield strength of 68 kN m kg(-1) under the compression test. The strong and durable TO-wood/MOF composites can potentially be used as a solid sorbent for CO2 capture, and their application can possibly be extended to environmental remediation, gas separation and purification, insulation, and catalysis.

Automated summary

A strong foam-like composite material is developed for CO2 sorption by growing thermally stable and microporous MOFs in a cellulose template derived from balsa wood. The composite exhibits high specific surface area and CO2 adsorption capacity, as well as durability during temperature swing cyclic CO2 adsorption/desorption test. This lightweight but exceptionally strong composite material has potential applications in CO2 capture, environmental remediation, gas separation, insulation, and catalysis.