The
reverse water–gas shift reaction (RWGS) reaction represents
a direct route for CO2 conversion whose selectivity significantly
depends on the selected catalyst. In this work, a new family of bimetallic
iron–copper oxide catalysts supported on ceria-alumina with
various Fe/Cu oxides ratios were investigated for the RWGS reaction.
Additionally, bare Fe-based and Bare Cu-based catalysts were synthesized
for comparison. Our results demonstrate that the developed bimetallic
Fe–Cu catalysts present a remarkable enhancement of catalytic
performance when compared to monometallic systems, especially at the
so-called “low-temperature range” for RWGS. Characterization
results evidence that Cu species undergo different states on the catalytic
surface during the reaction, wherein the formed metallic Cu is linked
to the catalytic activity via the strength of the interaction with
the multioxide phases, such as Fe3O4/CeO2, while the copper-dopped ceria could contribute to the promotion
of CO selectivity. Besides, we identify that the Fe/Cu oxides mass
ratio of 0.25/0.75 is an optimal formulation rendering highly commendable
CO2 conversion levels at 450 °C with excellent selectivity
and stability for long-term runs. Very importantly, without preactivation,
our multicomponent materials still display an optimum performance
which have a potential realistic application from cost perspective
than other Cu-based catalysts. Overall, this work showcases a strategy
to design highly effective multicomponent Fe–Cu catalysts for
CO2 conversion via RWGS.