Confinement engineered systems for CO2 valorization current advances and future directions

Thermocatalysis and electrocatalysis are central approaches for CO 2 conversion, offering the potential for mild reaction conditions and integration with renewable energy sources. Nanoconfinement, which constructs tailored nanoscale environments, emerges as a powerful strategy to regulate reactant adsorption and steer reaction pathways, thereby markedly improving the efficiency and selectivity of CO 2 conversion processes. This review comprehensively summarizes the latest progress in nanoconfinement strategies for both thermocatalytic and electrocatalytic CO 2 reduction, highlighting advances in catalytic activity control and identifying ongoing challenges and future research directions. In thermocatalysis, confinement enhances CO 2 hydrogenation by stabilizing reactive intermediates and mitigating catalyst sintering. For electrocatalysis, nanoconfinement promotes the selective formation of multi-carbon products by enriching key intermediates (such as ∗CO) and facilitating C–C coupling. Emerging synergistic systems that integrate thermal and electrochemical processes further capitalize on the complementary benefits of both electrical and hydrogen-induced transformations, paving the way for highly efficient CO 2 conversion. Despite notable advancements, obstacles remain—including scalable synthesis of nanoconfined catalysts, incomplete mechanistic understanding, and limited catalyst durability—which hinder large-scale deployment. Going forward, research should focus on advancing in-situ characterization techniques and computational modeling to elucidate confinement effects, while also prioritizing the development of scalable, robust catalytic systems.