Review of Emerging Nanomaterials for CO₂ Capture and Capture-to-Conversion: Materials, Devices, and System-Level Perspectives

The expeditious implementation of advanced carbon dioxide capture and capture-to-conversion technologies is imperative to facilitate climate change mitigation, foster cleaner industrial production, and establish resilient infrastructure aligned with sustainable development objectives. Traditional amine scrubbing technologies are hindered by elevated regeneration energy requirements, solvent degradation, and corrosion, necessitating the exploration of durable, energy-efficient alternatives. This review meticulously evaluates next-generation nanomaterials, including metal–organic frameworks (MOFs), porous organic polymers/covalent organic frameworks (POPs/COFs), carbonaceous adsorbents, and hybrid nanocomposites, while correlating material performance with device and system applications. A standardized benchmarking framework systematically compares equilibrium and working capacities, CO₂/N₂ selectivity, tolerance to moisture and impurities (SOₓ/NOₓ), cyclic stability, mass-transfer kinetics, implications for pressure drop, and regeneration energy, while also mapping these metrics to temperature-swing adsorption (TSA)/pressure swing adsorption (PSA)/vacuum swing adsorption (VSA) contactors, structured monoliths, mixed-matrix membranes, and intensified capture–conversion reactors. Innovations such as dynamic/switchable sorbents, photothermal and electro-swing regeneration, defect engineering, and tandem catalytic capture platforms are analyzed, with a focus on scalability, design, and realistic operational conditions in flue-gas environments. Integrated techno-economic analysis (TEA) and life cycle assessment (LCA) findings delineate capital expenditure (CAPEX) and operational expenditure (OPEX), as well as embodied carbon hotspots, with abatement costs typically estimated at 40-80 USD per ton of CO₂ under favorable energy and lifespan assumptions. A roadmap for 2030–2035 emphasizes the importance of durability certification, the deployment of modular retrofitting solutions, and validation at the pilot scale.