(149g) Cooperative Bifunctional Adsorbent/Catalyst Structured Monoliths for Direct Capture-Utilization of CO2 with Cogeneration of Ethylene and Propylene

Capturing and converting CO₂ into value added products is an attractive way of managing greenhouse emissions, however, adsorptive & reactive processes occur at vastly different temperatures. One way of utilizing CO₂ emissions is as a light-oxidant feedstock for oxidative dehydrogenation of propane (ODHP) to propylene. However, the adsorption and reaction steps typically occur at widely different temperatures, meaning that the thermal gradients- and by extension process energy requirements -are often unreasonably high. Cooperative bifunctional materials (BFMs) comprised of an adsorbent and a catalyst can mitigate the thermal gradient between such processes, but they have only ever been reported in the powder state.^1,2 In this study, we utilized our novel direct 3D printing strategy^3-5 to implement the first-generation of structured BFMs. Specifically, we formulated several (M)-CaO/ZSM-5 BFM monoliths and performed metal screening to determine which dopant produced the best performance at a fully isothermal capture/conversion condition of 600 °C. It was also found that varying the metal dopant could be used to control the heuristics of CO₂/C₃H₈ conversion, C₃H₆ selectivity, and C₃H₆ yield, meaning that the manufacturing process outlined herein represents a promising way of tuning the chemical properties of structured DFM adsorbent/catalyst materials. This study represents an exciting proof-of-concept and simple pathway to formulate highly active cooperative bifunctional adsorbent/catalysts.

References:

1. Lawson et al., ACS Sustainable Chem. Eng., 2021, 9, 5716-5727.
2. Lawson et al., ACS Appl. Mater. Interfaces, 2021, 13, 55198-55207.
3. Lawson et al., Appl. Catal. B: Env 2022, 303, 120907.
4. Lawson et al., Chem. Eng. J., 2022, 133224.
5. Lawson et al., Chemical Reviews, 2021, 121, 6246-6291.