TiO₂ Coating Strategy for Robust Catalysis of the Metal–Organic Framework toward Energy-Efficient CO₂ Capture

Abstract

High energy duty restricts the application of amine-based absorption in CO₂ capture and limits the achievement of carbon neutrality. Although regenerating the amine solvent with solid acid catalysts can increase energy efficiency, inactivation of the catalyst must be addressed. Here, we report a robust metal-organic framework (MOF)-derived hybrid solid acid catalyst (SO₄^2-/ZIF-67-C@TiO₂) with improved acidity for promoting amine regeneration. The TiO₂ coating effectively prevented the active components stripping from the surface of the catalyst, thus prolonging its lifespan. The well-protected Co-N<i>_x</i> sites and protonated groups introduced onto the TiO₂ surface increased the amount and rate of CO₂ desorption by more than 64.5 and 153%, respectively. Consequently, the energy consumption decreased by approximately 36%. The catalyzed N-C bond rupture and proton transfer mechanisms are proposed. This work provides an effective protection strategy for robust acid catalysts, thus advancing the CO₂ capture with less energy duty.