Beyond Amines: Engineering Bio-Inspired MOFs for Sustainable Direct Air Capture of CO2

Objective

Anthropogenic CO2 emissions have risen from 280 ppm (pre-industrial) to 401 ppm (2015), driving climate change. The European Green Deal targets carbon neutrality by 2050, demanding large-scale direct air capture (DAC) technologies. Current DAC capacity (~0.01 Mt CO2/year) is far below the 980 Mt/year target, with existing solid sorbents limited by low capacity at ambient CO2 (~400 ppm), high regeneration energy, poor humidity tolerance, and scalability issues. DACMOF introduces a bio-inspired, amine-free strategy using metal–hydroxyl (M–OH) sites—analogous to the carbonic anhydrase enzyme— embedded into the pore walls of robust scalable MOFs, to capture CO2 via bicarbonate formation with high CO2/H2O selectivity, mild regeneration (<80°C), and long-term stability. The project will: (1) fine-tune M–OH pore chemistry and hydrophobic microenvironments for >2 mmol/g uptake and >100 CO2/H2O selectivity at high humidity; (2) directly visualise competitive CO2/H2O adsorption using in situ synchrotron PXRD, FTIR, and computational modelling; and (3) develop sustainable, scalable MOF synthesis (green solvents, ambient pressure) and shaping to kg scale with <20% performance loss. By pioneering new coordination environments (e.g., 2N–M–2OH), alternative metals (e.g., Ni–OH), and dual-level pore design, DACMOF will overcome humidity-induced performance loss, deliver low-energy regeneration, and establish a synthesis-to-deployment pipeline. This approach advances beyond current amine-based and M–OH MOFs, providing a water-tolerant, scalable, and sustainable DAC solution ready for real-world application.