"The key objective of the M4CO2 project is to develop and prototype Mixed Matrix Membranes based on highly engineered Metal organic frameworks and polymers (M4) that outperform current technology for CO2 Capture (CO2) in pre- and post-combustion, meeting the energy and cost reduction targets of the European SET plan.By applying the innovative concept of M4 by a consortium of world key players, continuous separation processes of unsurpassed energy efficiency will be realized as a gas-liquid phase change is absent, reducing the energy penalty and resulting in smaller CO2 footprints. Further, gas separation membrane units are safer, environmentally friendly and, in general, have smaller physical footprints than other types of plants like amine stripping.In this way this project aims at a quantum leap in energy reduction for CO2 separation with associated cost efficiency and environmental impact reduction.The developed membranes will allow CO2 capture at prices below 15 €/ton CO2 (≈ 10-15 €/MWh), amply meeting the targets of the European SET plan (90% of CO2 recovery at a cost lower than 25€/MWh). This will be underpinned experimentally as well as through conceptual process designs and economic projections by the industrial partners.By developing optimized M4s, we will combine: i) easy manufacturing, ii) high fluxes per unit volume and iii) high selectivity through advanced material tailoring. The main barriers that we will take away are the optimization of the MOF-polymer interaction and selective transport through the composite, where chemical compatibility, filler morphology and dispersion, and polymer rigidity all play a key role.Innovatively the project will be the first systematic, integral study into this type of membranes with investigations at all relevant length scales; including the careful design of the polymer(s) and the tuning of MOF crystals targeting the application in M4’s and the design of the separation process."