The Need

Industrial CO₂ capture is widely deployed at point-source emissions—such as power plants and cement factories—as well as in emerging Direct Air Capture installations. The dominant commercial technology, liquid amine scrubbing, relies on strong chemical bonds to deliver high capture capacity and selectivity even at low gas concentrations. However, breaking these strong bonds creates a severe operational trade-off, requiring high regeneration temperatures (120-150°C) that impose heavy energy costs and cause chemical degradation over time. Conversely, low-energy physical sorbents require far less heat to regenerate but suffer from low binding affinity and poor capacity under ambient conditions.

The Technology

The Ohio State University researchers, led by Professor Casey Wade, have developed an adsorbent capable of CO2 capture. The patented MOF mimics the biological enzyme α-carbonic anhydrase, using active Zn-OH sites to chemically convert incoming CO₂ into trapped bicarbonate. Neighboring zinc sites cooperate through hydrogen bonding to lock in even trace amounts of gas, such as from ambient air. Heating the material to just 100°C breaks these temporary bonds, releasing pure CO₂ and fully restoring the sorbent for the next capture cycle

Benefits/Advantages

• Cooperative Binding Boost: Subsequent CO₂ uptake induces inter-cluster hydrogen bonding between neighboring zinc sites, which enhances structural stabilization and boosts capture performance.
• Low Regeneration Energy Requirements: The sorbent achieves full thermal swing regeneration at a mild 100°C under dynamic vacuum or purge, operating with a relatively low heat of adsorption (70 – 40 kJ/mol).
• Enhanced Chemical Stability: Unlike traditional amine-functionalized sorbents or liquid amine scrubbers, the inorganic metal-hydroxide backbone avoids degradation caused by amine oxidation or volatilization during thermal cycling. Maintains high adsorbent capacity through many adsorption-desorption cycles
• High Efficiency at Trace Pressures: The material demonstrates exceptional capture capacity at very low CO₂ concentrations, achieving 2.2 mml/g at 0.4 mbar (ambient Direct Air Capture levels) and 2.49 mmol/g at 5 mbar.
• Simple Synthesis Route: The active Zn-OHcenters are accessible via straightforward ligand exchange, avoiding complex post-synthetic redox oxidation steps required by other metal-hydroxide MOFs.