Recent advancements in integrating CO2 capture from flue gas and ambient air with thermal catalytic conversion for efficient CO2 utilization

Capturing CO 2 and converting it into valuable chemicals and fuels have been regarded as a pivotal strategy in addressing the environmental challenges of ever-growing CO 2 emissions. Combining CO 2 capture and conversion through material or process integration can eliminate the energy-intensive steps such as separation, compression, and transportation across a wide range of space and temperatures. The flue gas at high temperatures > 300 °C can be handled with dual-function materials consisting of sorbents and catalysts. The dual-function materials combine CO 2 capture and conversion through material integration, converting CO 2 with reactions such as methanation, reverse water-gas shift, dry reforming of CH 4 , and oxidative dehydrogenation of propane. On the other hand, capturing CO 2 from air directly requires a long time to collect enough CO 2 for the subsequent conversion reaction. Consequently, direct air capture will likely combine with the conversion reactions in stepwise operations. The low latent heat in CO 2 from direct air capture makes it more suitable for reactions at a mild condition (< 250 °C), and stepwise operation allows the separate control of the capture and conversion conditions. Herein, we reviewed recent advancements in coupling CO 2 capture from flue gas and ambient air with thermal catalytic conversion. We discussed the requirements for materials, reactor configuration, and process operation for capturing and converting CO 2 from these sources and proposed that future research should focus on enhancing the efficiency, scalability, and sustainability of CO 2 capture and conversion technologies and optimizing the process design. • Summary of progress in thermal catalytic approaches for integrated CO 2 capture and conversion. • Identification of different modes of integration for capturing and converting CO 2 from flue gas and ambient air. • Review of techno-economic assessments for ICCC and DACC. • Proposed future research focus areas.