Dual Functional Materials: At the Interface of Catalysis and Separations

Abstract

Dual functional materials (DFMs) are a promising approach to increase the energy efficiency of carbon capture and utilization by combining both steps into a single unit operation. In this Perspective, we analyze the challenges and opportunities of integrated carbon capture and utilization (ICCU) via a thermally driven process. We identify three key areas that will facilitate research progress toward industrially viable solutions: (1) selecting appropriate DFM operating conditions; (2) designing and characterizing interfacial site cooperativity for CO₂ adsorption and hydrogenation; and (3) establishing standards for rigorous and comprehensive data reporting.

Figure 1

Schematic of commonly studied reactions over DFMs with associated heats of reaction. Right-most thermodynamic state is calculated from the minimum energy required to separate the desired product, assuming 10% conversion of inlet CO₂.

Figure 2

Transition of the adsorption mechanism as a function of CO₂ partial pressure over CaO. For high CO₂ partial pressures the carbonation reaction is 1st order in CO₂. On the other hand, for a low CO₂ partial pressure the carbonation reaction becomes 0th order in CO₂. Reprinted with permission from ref (23). Copyright 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Figure 3

Proposed integrated CO₂ capture and direct methanation over Ni/CaO-based DFMs. Reprinted with permission from ref (25). Copyright 2023 American Chemical Society.