Strategies to Stabilize Inductively Heating Fe Nanoparticles for Catalyzing the CO₂ Conversion to Syngas via Reverse Water Gas Shift

Abstract

Fe-based solid materials are studied here as self-heating catalysts that can convert CO₂ into CO via a reverse water–gas shift (RWGS), a key reaction for carbon utilization. We describe the scalable synthesis of Fe nanoparticles capable to be inductively heated to 500–800 °C while catalytically active in RWGS. For iron species to develop a dual function as heaters and catalysts, the formation of nonferromagnetic Fe phases under reaction conditions must be avoided. Such phases lead to rapid cooldown of the reactor and the deactivation of the catalyst. Here, the stabilization of the self-heating RWGS catalysts was achieved by adjusting the nanoparticle properties via mesoporous supports, the addition of Co as a promoter, and redox pretreatments. Through extensive operando and in situ characterization, we show the dynamics of self-heating catalytic nanoparticles under reactive atmospheres, as those verified during RWGS reaction and pave the way for other applications in energy-intensive catalytic processes.