Study on the Preparation of Biomass-Derived Porous Carbon and Enhanced Carbon Capture Performance via MOF-Assisted Granulation.

Biomass porous carbon materials have a high specific surface area and a rich pore structure, making them promising CO2 capture materials. However, the complexity of biomass composition and microstructure may lead to poor reproducibility in the quality of biomass-derived porous carbon. Developing reliable methods for preparing biomass-derived porous carbon is crucial. This study is the first to extract plant fibers from rice straw using an alkaline method and successfully prepare a nitrogen-doped porous carbon material from this raw material. However, similar to most porous carbons used directly for carbon dioxide capture, this material faces challenges in engineering applications, such as complex powder properties, high energy consumption, and significant losses. Here, we further explore the metal-organic framework (MOF)-assisted granulation method to convert porous carbon into carbon microspheres. This method not only enhances the mechanical properties of the material but also compensates for the loss of adsorption capacity during the granulation process, thereby significantly improving the application prospects of biomass porous carbon in the field of carbon capture. This study evaluated in detail their carbon dioxide adsorption capacity and particle compressive strength. The results showed that the porous carbon microspheres doped with Co-MOF-74 exhibited high CO2 uptake at 1 bar, up to 3.87 mmol g-1 at 25 °C and 3.15 mmol g-1 at 40 °C. In addition, the particle strength of porous carbon microspheres can be increased by more than five times, which is attributed to the crucial role of Co-MOF-74 doping in regulating the pore structure. In this study, we report that an unprecedented design of biomass porous carbon microspheres can provide a solution to the particle agglomeration and reactor clogging problems caused by the complex powder properties of porous carbon and significantly expand the application scenarios of biomass porous carbon in the field of carbon capture.