The overall objective is to combine crosslinked polymers having molecular sizesieving ability, and palladium (Pd)-based nanomaterials with very high hydrogen (H2)/carbon dioxide (CO2) solubility selectivity, to achieve membranes with superior gas-separation performance relative to stand-alone polymeric membranes. This project may lead to new generation of membrane materials that combine robust performance with good processability to significantly decrease the cost of CO2 capture, utilization, and storage (CCUS), enabling environmentally responsible energy production from abundant domestic coal.