Highly Active and Selective Multicomponent Fe–Cu/CeO₂–Al₂O₃ Catalysts for CO₂ Upgrading via RWGS: Impact of Fe/Cu Ratio

Abstract

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.

Photothermal synthesis of a CuOx&FeOy catalyst with a layered double hydroxide-derived pore-confined frame to achieve photothermal CO2 hydrogenation to CO with a rate of 136 mmol min−1 gcat−1

“…Fe-based materials were often applied as promoter to improve the thermal stability and catalytic activity of RWGS catalysts. 8,11,30,[33][34][35] On the one hand, the Fe-base promoter exhibits much better dispersity than the active phase of Cu (which can be evidenced by the characterization of TEM and elemental mapping of CuO x &FeO y /MAO, Fig. 3).…”

“…It can be attributed to that the Cu-FeO y interfacial region provides more active sites for H 2 dissociation than individual Cu and Fe, and therefore transfers active H to Cu, which makes the Cu remain low chemical valence. 33,36 . This can be supported by the fact that the introduction of excessive Fe resulted in the formation of CH 4 (Fig.…”

Electroplating Sludge-Derived Multiple-Metal-Doped Spinel with Superior CO Selectivity in Reverse Water–Gas-Shift Reaction

“…Thus, CO 2 conversion was promoted and CO selectivity was maintained by loading active metals on ZnCr spinel. According to eq 7, 50 the values of all catalysts were bigger than 98%, that is, coking formation was negligible.…”

“…CO dissociation was mild due to the synergistic active sites effect (metal/oxide redox pairs). 50 Various metal phases were initially present as mixed components in heavy-metalcontaining sludges (Figure 10a). The hybrid structure of sludge was transformed into spinel as the skeleton.…”

The High-Effective Catalytic Degradation of Benzo[a]pyrene by Mn-Corrolazine Regulated by Oriented External Electric Field: Insight From DFT Study

“…In addition, the possible oxidative degradation mechanisms and pathways of BaP in the atmosphere have been explored by Dang et al (2015) . However, despite the involvement of transition metals in many catalytic processes ( Fujihara and Tsuji, 2019 ; Lin et al, 2021 ; Parmar et al, 2021 ; Sánchez-López et al, 2021 ; Yang et al, 2021 ; Zhou et al, 2021 ; Zhou et al, 2022 ), the use of transition metal complexes as non-sacrificial oxidants for the degradation of BaP has not been reported in the literature.…”