Hollow branched fiber hierarchical porous carbon as recyclable adsorbents and catalysts for efficient CO2 capture and conversion

The promotion of carbon neutrality been fueling the rapid growth of the new energy vehicle industry. However, this expansion inevitably brings about the devilish problem of waste disposal and environmental pollution. Melamine foam, as a typical sound insulation material for new energy vehicles, has also been considered a valuable organic precursor in recent years due to its high carbon and nitrogen content. In this study, we reused waste melamine foam through a simple carbonization-pyrolysis process, to obtain a series of hollow fiber hierarchical porous carbon materials (MFC) with different functions. Surprisingly, the MFC materials exhibit excellent CO2 capture and conversion capability. For example, MFC-900 has a CO2 capture capacity of 1.37 mmol g-1 at 1 bar and 50 C, which increases significantly to 5.05 mmol g-1 at 1 bar and 0 C. Additionally, the CO2 selectivity of MFC-900 material is 285 at 50 C, outperforming comparable hierarchical porous carbon materials. This superior performance is attributed to the unique hollow branched fiber structure and multiple types of basic centers of MFC materials. Furthermore, the MFCs demonstrate high catalytic efficiency, facilitating the conversion of CO2 and epoxides into cyclic carbonates with yield of up to 99%. Therefore, based on the superior CO2 capture and conversion performance of the MFC materials in this work, a new method of converting waste carbon resources into functional carbon is proposed for the field of carbon neutrality.