Boosting whole-process CO₂ capture via dual-pathway synergy by spatially hierarchical sites on carbon-based...

To address the demand for energy-efficient and scalable CO₂ capture catalysts, we construct a spatially hierarchically functional interface on a carbon-based support, comprising -SO₃H and SiO_x-OH sites. This design exploits their distinct acid strengths and thermal responses: at low temperatures, Si-OH networks facilitate CO₂ uptake via proton pre-organization and intermediate stabilization; at elevated temperatures, -SO₃H sites drive C-N bond cleavage and rapid CO₂ release. The spatial proximity of the two sites creates a proton-relay channel, enabling sequential activation with progressively reduced energy barriers. In situ FT-IR and DFT calculations reveal that HCO₃^- replaces MEACOO^- as the dominant interfacial desorption intermediate, establishing a dual-pathway mechanism that reduces the thermodynamic penalty of conventional amine regeneration. Under simulated industrial conditions, the optimized catalyst achieves 36.3% desorption efficiency and 39.6% energy savings versus the blank, with excellent stability over five cycles. This work provides a theoretical and material foundation for integrating catalytic desorption into amine-based CO₂ capture systems.