Heavy-duty freight transportation, a key part of global transportation networks, is an energy-intensive contributor to growing CO2 emissions. Here, an onboard post-combustion capture and storage system is proposed for heavy-duty freight vehicles. Two state-ofthe-art metal-organic frameworks with high CO2 selectivity and high storage capacity, respectively, are chosen. With high stability and selectivity toward CO2, even in humid conditions, KAUST-7 is the capturing material. Al-soc-MOF-1 is the storage material, given its high gravimetric and volumetric CO2 uptake between 10 and 50 bar. The goal of the system is to reduce heavy-duty vehicle CO2 emissions by at least 50% and achieve above 95% CO2 purity at the storage point. KAUST-7’s thermodynamic and kinetic properties are measured and modeled, and process conditions are simulated and optimized in response to dynamic engine behavior. Captured and stored mass and volume are also minimized, resulting in methods to mitigate carbon emissions in the heavy-duty freight industry.