Proton Shuttle Effect-Induced Homogeneous Catalysis for Low-Energy CO ₂ Capture

The high regeneration energy consumption of amine-based carbon capture represents a critical bottleneck hindering the large-scale implementation of CCUS technologies. To overcome the proton transfer limitations inherent in conventional thermal regeneration, which relies on elevated temperatures, this study proposes a novel homogeneous catalytic system utilizing proton shuttles. By replacement of heterogeneous solid acid catalysts with small organic molecules (e.g., ethanol), this system enables efficient proton transfer while circumventing solid–liquid interfacial diffusion resistance. The dynamic proton exchange capability of these shuttles, operating BH/B– cycling, accelerates the deprotonation of RNHCOO– species and significantly reduces the reaction energy barrier. Experimental results demonstrate that ethanol, because its pKa value balances proton donation and acceptance capabilities, reduces regeneration energy consumption by 35%, with isotope-labeled mass spectrometry confirming the proton transfer pathway. This homogeneous catalytic mechanism, through molecular-level optimization of proton transfer dynamics, provides a new pathway for developing efficient and stable CO2 desorption processes, potentially accelerating the economic advancement of carbon capture technologies toward achieving carbon neutrality goals.