Constructing the electron transfer channels between TiO2 nano-islands to promote efficient and robust CO2 capture

CO 2 emissions from industrial processes are becoming a growing global concern due to their impact on climate change. Catalyst-aided amine solvent regeneration is an effective approach for achieving low-energy carbon capture. Existing desorption catalysts regenerate amine solutions by accelerating proton transfer during CO 2 desorption, but limited proton transfer efficiency under alkaline conditions leads to inevitable deactivation of active sites. Herein, we developed TiO 2 /Ti 3 C 2 , a TiO 2 nano-islands structured catalyst via in situ oxidation of Ti 3 C 2 T x MXene nanosheets. The remaining MXene enhances electron transfer between TiO 2 nano-islands, promoting CO 2 desorption-induced solvent regeneration through proton-coupled electron transfer effect via Raman spectroscopy and low-temperature electron paramagnetic resonance experiments. Theoretical calculation demonstrates that TiO 2 /Ti 3 C 2 reduce the energy barrier of solvent regeneration by 44.9 % compared to the non-catalytic scenario. The CO 2 desorption rate increased by 150 %, while the relative energy penalty of the solvent regeneration decreased by 75 %. The regeneration temperature was reduced from 120 °C to 98 °C with an amine-based biphasic solvent, effectively preventing ~28 % of amine degradation. Additionally, TiO 2 /Ti 3 C 2 demonstrates exceptional stability, showing negligible performance degradation and structural changes after 10 cycles. This work offers valuable insights for designing catalysts to achieve efficient and robust CO 2 capture.