Recasting the Catalytic Legacy of Reverse Water-Gas Shift Reaction: Rational Design Strategies for Selective CO₂...

Rising atmospheric CO₂ and climate pressures have intensified interest in carbon capture and utilization (CCU). The reverse water-gas shift (RWGS) reaction offers a direct route to convert CO₂ into CO, a versatile syngas component for Fischer-Tropsch, methanol synthesis, and other downstream processes, thereby supporting a circular carbon economy. RWGS is inherently challenging: it is endothermic and favored only at high temperatures (>600 °C), which promotes catalyst sintering and high energy demand, while at lower temperatures the competing Sabatier reaction dominates, producing CH₄ over Ni. Catalyst selection further complicates implementation: noble metals (Au, Pt, Rh) offer high CO selectivity but are costly, whereas base metals (Ni, Fe, Cu) are more abundant yet prone to methanation, sintering, or phase instability. Industrial deployment also demands resilience under water-rich environments, high space velocities, and thermal cycling associated with variable renewable H₂ supply. This Account presents our efforts to address these challenges through rational catalyst design guided by three central principles: electronic modulation via promoters to control adsorption and reaction pathways; active phase engineering to tune catalytic functionality and suppress undesired reactions, and structural and interfacial design to enhance stability and durability under realistic conditions. These principles are systematically explored using Ni- and Fe-based catalysts as model systems for scalable CO₂ valorization. Alkali-promoted Ni catalysts, particularly Cs-modified Ni/CeO₂, demonstrate how electronic tuning and metal-support interactions suppress methanation and enable CO-selective RWGS across a wide temperature range. Phase engineering further transforms Ni into phosphide intermetallic (Ni₂P, Ni₁₂P₅), introducing active sites that favor CO formation while minimizing hydrogenation pathways. Complementary strategies in Fe-based systems, including MOF-derived Fe/carbon composites and Fe-Cu bimetallics, highlight the role of metal-support and metal-metal interactions in stabilizing active phases and enhancing CO yields. To address deactivation, nanoscale architectural control, such as core-shell and yolk-shell structures, has been employed to mitigate sintering and carbon deposition. Beyond single-function catalysts, dual-function and switchable materials integrate CO₂ capture with catalytic conversion and enable dynamic operation across RWGS, methanation, and dry reforming, providing flexibility under variable process conditions. Mechanistic insights derived from operando spectroscopy reveal how surface defects, promoters, and support redox properties govern reaction pathways, including formate-mediated and redox mechanisms, thereby linking catalyst structure to function. Collectively, these studies demonstrate how integrating electronic, compositional, and structural design strategies can reconcile the competing demands of activity, selectivity, and stability in RWGS catalysis. By bridging mechanistic understanding with practical engineering considerations, this work advances RWGS from a fundamental reaction toward a scalable platform for CO₂ valorization. These insights provide a framework for the design of next-generation catalytic materials and highlight the broader potential of rational materials engineering in enabling sustainable carbon utilization technologies. Looking ahead, operando-guided discovery, AI-assisted materials design, and integration with renewable energy infrastructures will be critical to realizing its full potential.