(569bz) CO2 Hydrogenation to Methane: Optimizing Metal-Metal Oxide Interfaces through Defect Engineering in Perovskite Oxides

The utilization of carbon dioxide as a feedstock for the production of valuable chemicals, such as methane, holds significant promise for mitigating greenhouse gas emissions and fostering sustainable energy systems. Numerous heterogeneous catalysts, including Rh, Ru, and Ni supported on various metal oxides, have been extensively studied for CO₂ methanation over the years¹. Strategic design of catalysts offering direct C-O bond scission and hydrogen dissociation at low temperatures via metal-metal oxide interfaces and suitable metal active sites, actively boost methane production. The significance of these strong metal-support interactions at interfaces in chemistries involving direct and selective CO₂ hydrogenation to CH₄ is widely acknowledged, however the exact effect of these interfaces and the defect structure around these interfaces are still under debate².

Herein, to shed light on the effects of metal-metal oxide interfaces on CO₂ methanation, we study the impact of modulating the interface of metals with perovskites on CO₂ hydrogenation activity and selectivity. We use thermal effects under reducing conditions to induce lattice shrinking/expansion to the perovskite matrix, facilitating the generation of oxygen defects and strong metal-support interactions. We vary the composition of the cations in the perovskite and the supporting metal to develop an understanding of how such changes to the interface impact CO₂ hydrogenation activity and selectivity at different metal-metal oxide interfaces. This is achieved through integration of experimental characterization techniques and catalytic studies, which are used to elucidate the intricate interplay between interfacial defects, oxygen vacancies, and catalytic performance for CO₂ hydrogenation. Insights gained from this study provide valuable guidelines for the design of selective heterogeneous catalysts for CO₂ upgrading, and environmental remediation efforts.

References

1. Ashok, J. et al., Catalysis Today 356, 471–489 (2020).
2. Kattel, S. et al., J. Am. Chem. Soc. 139, 9739–9754 (2017).