(500c) Towards Self-Regenerative Sorption-Enhanced Catalysts for Integrated CO2 Capture and Dry Reforming of Methane

Improving the thermal stability of sorption-enhanced catalysts (CO₂ sorbent + embedded heterogeneous catalyst nanoparticles)¹ is one of the most difficult and crucial parameters to control for integrated carbon capture and conversion processes. For example, sintering of the catalyst nanoparticle and CO₂ sorbent is associated with a loss of surface area and lower CO₂ capture capacity and activity. At industrial processes that operate at high temperatures, such as dry reforming of methane, the degree of deactivation of the sorbent and catalyst is particularly amplified.

This talk will introduce the use of self-regenerative Ni-doped CaTiO₃/CaO nanocomposites as multifunctional materials (MFMs) for the integrated CO₂ capture and subsequent dry reforming of methane (ICCDRM), where Ni-doped CaTiO₃ is a catalytically active material, and CaO is a sorbent for CO₂ capture. The incorporation of Ni into CaTiO₃ and in-situ exsolution of Ni from CaNi_xTi_1-xO₃ double perovskite were investigated. In-situ exsolved Ni nanoparticles, which interact strongly with the host CaTiO₃ perovskite, were evenly distributed throughout CaTiO₃ under H₂ or CH₄ (reductive conditions) – Fig 1a. The exsolved Ni nanoparticles were re-dispersed back into the bulk of CaTiO₃ under CO₂, indicating a self-regenerative process. Ni-doped CaTiO₃/CaO MFMs showed relatively stable CO₂ capture capacity and syngas productivity during 30 cycles of ICCDRM – Fig 1b. Strong interaction between Ni and CaTiO₃ and self-regeneration prevented Ni nanoparticles from sintering and decreased the deactivation of Ni due to both sintering and coke accumulation. Lastly, we summarize our findings to discuss rational design concepts for using MFMs for in situ carbon capture and conversion.

1. Jo, L. Cruz, S. Shah, S. Wasantwisut, A. Phan and K. L. Gilliard-AbdulAziz, ACS Catalysis, 2022, 12, 7486-7510.