2025 AIChE Annual Meeting

(195c) Tuning Catalytic Selectivity Via Dynamic Mobility of Catalytically Active Dopants in Perovskite Oxides for CO2 Hydrogenation

Authors

Rachel A. Yang, Rutgers, The State University of New Jersey
Miguel Sepulveda-Pagan, University of Puerto Rico at Mayagüez
Camilo A. Ortega-Vega, University of Puerto Rico Mayaguez
Yomaira Pagan Torres, University of Puerto Rico at Mayaguez
The conversion of CO2 into valuable C1 chemicals like CO and CH4 offers a promising strategy for reducing greenhouse gas emissions and promoting sustainable chemical processes. The product selectivity of CO2 hydrogenation is influenced by the design of metal active sites and metal-support interactions, which enable efficient C=O bond scission and hydrogen dissociation at low temperatures (200-300 °C) [1,2]. In traditional supported transition metal systems, metal cluster size determines selectivity: small clusters favor CO production, while larger nanoparticles (NPs) lead to CH4 formation [3]. However, the exact role of metal-support interfaces and surrounding defect structures remains unclear.

This study explores the tunability of CO2 hydrogenation selectivity using Rh-doped SrTiO3 perovskite oxides. These flexible frameworks inherently contain single cationic sites that, under reductive conditions, generate well-dispersed metal clusters at the oxide interface due to anchored interactions. By examining different exsolution conditions, we investigate how Rh cluster size and metal-oxide interactions influence CO2 hydrogenation. A combination of in situ DRIFTS experiments, catalytic studies and detailed characterization are used to elucidate the relationship between Rh exsolution conditions and product selectivity. Tuning the catalyst pretreatment and reaction environment is shown to enable control over product selectivity. This demonstrates the potential of perovskite-based catalysts to serve as flexible platforms for selective CO2 conversion. The insights from this study provide guidelines for designing efficient heterogeneous catalysts for CO2 upgrading and environmental sustainability.

  1. Bhat, S., Sepúlveda-Pagán, M., et al., J. Catal. Technol. 14, 3364 (2024)
  2. Kattel, S., Liu, P., Chen, J.G., J. Am. Chem. Soc. 139, 9739 (2017)
  3. Matsubu, J.C., Yang, V.N., Christopher, P., Am. Chem. Soc. 137, 3076 (2015)