碳球上碱金属氧化物的界面稳定化用于高性能CO2化学吸附OA

Efficient capture of low-concentration carbon dioxide(CO2)requires chemisorbents that couple strong reactivity with long-term structural stability.Alkali metal oxides are promising candidates but suffer from rapid sintering that severely reduces accessible active sites.Here we develop a universal interfacial strategy that immobilizes Li2O,Na2O,and K2O as highly dispersed amorphous domains on hollow carbon spheres(named Li-HCS,Na-HCS,and K-HCS)forming robust M-O-C anchor sites.These interfacial structures prevent oxide migration,enhance surface basicity,and significantly strengthen CO2 binding.Among the alkali metal-loaded hollow carbon spheres,K-HCS exhibits the highest CO2 uptake(4.9 mmol g-1 at 273 K and 1bar),fastest adsorption kinetics(13.56 mol kg-1 h-1 at 313 K and 1bar),and optimal low-pressure removal efficiency(44%at 273 K and 0.15 bar).Density functional theory calculations further reveal a monotonic increase in adsorption strength and molecular activation from Li to Na to K,driven by enhanced electron donation and polarizability.This work establishes a broadly applicable route for stabilizing alkali metal oxides and provides mechanistic insights for advancing low-pressure CO2 capture materials.