Reaction-driven exsolution from spinel ferrites for CO2 hydrogenation to short-chain hydrocarbons

Abstract

The development of catalysts capable of selectively converting CO2 into short-chain hydrocarbons remains a central challenge in sustainable catalysis. Here, we report a reaction-driven exsolution strategy in multi-metallic spinel ferrites that enables the in situ formation of active nanocomposite phases during CO2 hydrogenation and thus eliminates the need for any pre-treatments. We also demonstrate that depending on the exsolution environment, we can produce single metal and/or ternary nanoparticles. Operando spectroscopy reveals a bifunctional tandem mechanism in which Cu and Ni sites catalyze CO2 activation, while the iron carbide phases, dynamically forming under reaction conditions, promote C–C coupling and hydrocarbon chain growth. This reaction-induced restructuring leads to enhanced activity and selectivity toward short-chain hydrocarbons. These findings identify reaction-driven exsolution as a strategy for controlling active phase formation under working conditions, and they define a direct relationship between exsolution dynamics and catalytic performance and provide new insight into the design of energy-efficient, adaptive catalysts.