Microenvironment modulation of interpenetrating-type hierarchical porous foam carbon by mild-homogeneous activation for H2 storage and CO2 capture under ambient pressure.

ABSTRACT

Currently, carbon-based porous materials for hydrogen (H2) storage and carbon dioxide (CO2) capture are mostly applied at higher pressures (30-300 bar). However, applications for H2 storage and CO2 capture under ambient pressure conditions are significant for the development of portable, household, and miniaturized H2 energy technologies. This demands a higher standard for the interface microenvironment of adsorbents. Derived from polyurethane foams (PUFs) solid waste, the hierarchical porous foam carbon with interpenetrating-type pore structures exhibits high specific surface area (SBET = 1753 m2/g), abundant oxygen and nitrogen functional groups, and a hierarchical nanopore structure (VUltra = 0.232 cm3/g, VMicro = 0.628 cm3/g and VMeso = 0.186 cm3/g) through the mild-homogeneous sonication-assisted activation process. Under the limited adsorption of pore interface microenvironment composed by hierarchical nanopore structure and dipole-induced interaction (H(Ⅱ)-H(Ⅰ)···N/O and O(Ⅱ) = C(Ⅰ) = O(Ⅱ)···N/O), it exhibits an excellent H2 storage density (2.92 wt% at 77 K, 1 bar) and CO2 capture capacity (5.28 mmol/g at 298 K, 1 bar). This research approach can serve as a reference for the dual-functional design of porous foam carbon, and promote the development of adsorption materials for CO2 capture and energy gas storage under ambient conditions.