Imidazole-Based Hydrogen-Bonded Organic Frameworks for Rapid CO2 Capture and Low-Temperature Regeneration

Abstract

Efficient CO2 sorbents that combine rapid uptake and low-temperature regeneration are highly desired. Current solid sorbents face a critical tradeoff between strong chemisorption and associated regeneration energy. Here, an imidazole-based hydrogen-bonded organic framework (Im-HOF) is developed to enable Lewis acid–base-mediated CO2 capture with rapid adsorption kinetics and low-temperature regeneration. Im-HOF preserves ordered porosity to facilitate fast gas transport and provides accessible Lewis basic centers for reversible CO2 binding. Im-HOF exhibits a rapid CO2 uptake of ∼1.4 mmol g–1 within 10 min and releases over 90% of the captured CO2 within 3 min at 50 °C, highlighting its exceptional combination of fast capture and mild regeneration. Im-HOF also maintains excellent stability over 50 adsorption–desorption cycles. A Joule-heating-enabled device using Im-HOF is further demonstrated to achieve on-demand CO2 capture operation. This work shows that HOFs are an emerging platform for CO2 capture with fast kinetics and low regeneration energy.