Sulfate-Promoted Higher Alcohol Synthesis from CO 2 Hydrogenation

With mounting concerns about reducing carbon emissions, developing a catalyst that can be used in the hydrogenation of CO 2 to olefins makes sense. Considering the high cost of CO 2 capture, the direct use of low-concentration CO 2 to produce olefins is more promising. In this work, we develop a reliable Mg-modified Fe-based catalyst for the low-concentration hydrogenation of CO 2 to olefins. The optimized KFeMnMg 0.15 catalyst exhibits a high olefin yield of 15.4% with an olefin selectivity of 61.2% at a low CO 2 concentration of 10%. The structural characterizations reveal that the Mg promoter regulates the adsorption strength of reactants CO 2 and H 2 , and the intermediate is CO, which promotes the conversion of CO 2 and inhibits the hydrogenation of olefins. In addition, the Mg promoter plays a critical role in facilitating the formation of iron carbide, which is the active phase of the hydrogenation of CO 2 to olefins. Thus, multiple functions of the Mg promoter realize the efficient conversion of low-concentration CO 2 to olefins.

Section: Resultsmentioning

confidence: 99%

Development of Mg-Modified Fe-Based Catalysts for Low-Concentration CO₂ Hydrogenation to Olefins

Liu,

Xu,

Fan

et al. 2024

“…The dynamic IR peak intensities are shown in Figures and S17. The signal of C 2 H 5 O* over the 0.3K-1Pd/Fe 2 O 3 catalyst increases rapidly with time, and the ratio of CH x * to CO is significantly weakened with a weak CH x * signal compared with 1Pd/Fe 2 O 3 , indicating that the addition of highly dispersed K (0.3 wt %) inhibits the hydrogenation of the CH x * species and increases the ratio of CO*/CH x * on the catalyst surface, which promotes CO insertion . For the 0.3K/Fe 2 O 3 catalyst, CO is the main product with a small amount of C 2 H 5 O*, and the introduction of 1% Pd increases the C 2 H 5 O* formation rate (Figure c).…”

Section: Resultsmentioning

confidence: 99%

Highly Dispersed K- and Pd-Comodified Fe Catalyst for CO₂ Hydrogenation to Higher Alcohols

Zhou,

Wang,

et al. 2024

Self Cite

The conversion of CO2 to higher alcohols (HA) is a sustainable way for CO2 utilization, but the development of an efficient catalyst with multifunctional active sites to regulate the C–C coupling process remains a great challenge. Herein, we report a Fe catalyst modified with highly dispersed K and Pd for the efficient synthesis of HA. The optimal 0.3K-1Pd/Fe2O3 catalyst displays the best catalytic performance with an HA STY of 48 mg gcat –1 h–1 at 320 °C, 5 MPa, and 6 L gcat –1 h–1, which is 3.5 times that of 1Pd/Fe2O3 and 35 times that of the 0.3K/Fe2O3 catalyst. We found that in situ generated PdFe alloy and K synergistically stabilize the iron carbide phase, which is responsible for the CO dissociation and alkyl formation, while the PdFe alloy acts as an active site for CO nondissociative activation and CO insertion. Appropriate amounts of K and Pd can regulate the balance of CO* and CH x * species on the catalyst surface, which effectively facilitates C–C coupling to synthesize HA.

“…Catalytic CO 2 hydrogenation has gained significant attention as a credible scientific approach to counter these global challenges. , This method transforms CO 2 into useful energy fuels and chemicals, including carbon monoxide (CO), methane (CH 4 ), and light olefins . Beyond addressing atmospheric CO 2 accumulation, it heralds a path to a sustainable hydrocarbon-based energy future, promoting a more balanced global carbon footprint. , Nevertheless, this vision is not without hurdles . The inherent thermodynamic stability of CO 2 complicates its direct conversion to energy fuels and chemicals, particularly under milder pressure and temperature .…”

Section: Introductionmentioning

confidence: 99%

Harnessing the Synergy of Fe and Co with Carbon Nanofibers for Enhanced CO₂ Hydrogenation Performance

Arizapana,

Schossig,

Wildy

et al. 2024

Amid growing concerns about climate change and energy sustainability, the need to create potent catalysts for the sequestration and conversion of CO 2 to value-added chemicals is more critical than ever. This work describes the successful synthesis and profound potential of high-performance nanofiber catalysts, integrating earth-abundant iron (Fe) and cobalt (Co) as well as their alloy counterpart, FeCo, achieved through electrospinning and judicious thermal treatments. Systematic characterization using an array of advanced techniques, including SEM, TGA-DSC, ICP-MS, XRF, EDS, FTIR−ATR, XRD, and Raman spectroscopy, confirmed the integration and homogeneous distribution of Fe/Co elements in nanofibers and provided insights into their catalytic nuance. Impressively, the bimetallic FeCo nanofiber catalyst, thermally treated at 1050 °C, set a benchmark with an unparalleled CO 2 conversion rate of 46.47% at atmospheric pressure and a consistent performance over a 55 h testing period at 500 °C. Additionally, this catalyst exhibited prowess in producing high-value hydrocarbons, comprising 8.01% of total products and a significant 31.37% of C 2+ species. Our work offers a comprehensive and layered understanding of nanofiber catalysts, delving into their transformations, compositions, and structures under different calcination temperatures. The central themes of metal−carbon interactions, the potential advantages of bimetallic synergies, and the importance of structural defects all converge to define the catalytic performance of these nanofibers. These revelations not only deepen our understanding but also set the stage for future endeavors in designing advanced nanofiber catalysts with bespoke properties tailored for specific applications.