(622e) Theoretical Analysis of Reactive CO2 Capture Via Na2o/TiO2 based Dual Functional Materials.

The global effort to address climate change revolves around reducing CO₂ emissions, with a focus on advancing carbon capture and storage (CCS) technologies. One promising avenue is Reactive Capture and Conversion (RCC), which involves capturing and converting carbon simultaneously. Dual-functional materials (DFM), such as "Na-Ru/TiO₂," show potential for CO₂ capture and subsequent conversion to methane through methanation processes.

Our research focuses on understanding the adsorption and catalytic properties of Na-Ru/TiO₂ under various conditions, including elevated temperatures post-methanation cycles. The role of alkali particles on TiO₂ in CO₂ adsorption is being investigated theoretically, aligning with empirical findings indicating diverse configurations of Na₂O clusters or Na₂O-TiO₂ composite titanate systems, which influence CO₂ absorption and methanation. Ab initio molecular dynamics (AIMD) simulations help understand catalyst behavior under realistic conditions. Two catalyst models were developed, one representing clustered metal particles and the other dispersed ones (Figures 1a & 1b, respectively). Preliminary results indicate that atomic dispersion of Na atoms enhances CO₂ binding energy and uptake, consistent with experimental observations. Moreover, Bader charge density difference plots illustrate lower and stronger electronic interactions based on the Na dispersions, respectively, where electrons from Na atoms transfer to the TiO₂ substrate, leaving Na as cationic sites.

Al₂O₃-based DFMs also showed significant CO₂ uptake experimentally, highlighting the role of support materials in RCC performance. Therefore, future modeling will explore physicochemical properties of different supports (Al₂O₃, CeO₂) and their correlation with RCC performance. Additionally, modeling efforts will also aim to integrate Ru atoms into the Na₂O/TiO₂ system to study CO₂ binding and methanation kinetics. Our research underscores the potential of DFMs like Na-Ru/TiO₂ in CCS efforts. By understanding the interplay of materials and conditions, advancements can be made towards efficient CO₂ capture and conversion, contributing to global efforts in combating climate change.

a) Na₂O/TiO₂ nanoparticle model b) Na₂O/TiO₂ dispersed model.