CO Hydrogenation Research Articles

Positive effect of carbon monolith porosity sealing with MgO in the CO2 hydrogenation to CH4 using NiO‐CeO2 active phase

Positive effect of carbon monolith porosity sealing with MgO in the CO2 hydrogenation to CH4 using NiO‐CeO2 active phase

Studies on a Urea-Complexed Iron(III) Dichromate, a Precursor of Chromium-Rich Nanospinel Catalysts Prepared for the Reductive Transformation of Carbon Dioxide.

Energy-saving and cost-efficient reaction routes to prepare highly active catalysts for CO2 hydrogenation or solid oxide fuel cells (SOFCs) are enormously important. In this paper, we report a detailed study of a dichromate salt of [Fe(urea)6]3+, a member of the [M(urea)6]3+ complex family (M = Fe, Al, Mn, Cr, V, or Ti) with oxidizing anions, which is a promising precursor of a Cr-rich mixed chromium iron oxide catalyst prepared at a low temperature in the solid phase. The single-crystal X-ray structure, various (infrared, ultraviolet-visible, and Raman) spectroscopic studies, and thermal analysis (differential scanning calorimetry and thermogravimetric analysis/mass spectrometry) of [hexakis(urea-O)iron(III)] dichromate {[Fe(urea-O)6]2(Cr2O7)3} and its decomposition products confirmed the presence of a quasi-intramolecular redox reaction between the urea ligands and dichromate anions. The redox reactions result in various mixed Cr-Fe oxides with amorphous structure, whereas above 550 °C, the crystal structure and composition of the final products depend on the atmosphere during the thermal decomposition. The iron-chromium mixed oxides are potential catalysts in CO2 hydrogenation that afford CO, CH4, C2H6, and C3H8. Furthermore, our Mössbauer spectroscopy studies show a possible electron hopping between the FeII and FeIII ions at the tetrahedral sites of the spinel structure, which suggests that the formed chromite is also a potential SOFC material. Our study also demonstrates that hexaureairon(III) dichromate is a selective oxidation agent of sulfur-containing organic compounds.

CO2 methanation on Mg-doped Ni-Cu/Co modified mesoporous SiO2 derived from rice husks.

Mesoporous silica (SiO2) was prepared using a simple procedure from rice husks without the application of a template. Incipient wetness impregnation method was employed to prepare magnesium-doped nickel-copper- and nickel-cobalt-containing SiO2 catalysts. The obtained materials were characterized by X-ray powder diffraction (XRD), N2 physisorption, transmission electron microscopy (TEM), temperature-programmed reduction (TPR-TGA), and NMR and XPS spectroscopies. The study demonstrated the significant influence of Ni and Co/Cu content, as well as the sequence of Mg promotion (before or after the nickel-copper- and nickel-cobalt-modification) on the physico-chemical properties of the catalysts. The peculiar properties of the mesoporous carrier positively influenced the formation of finely dispersed nickel and/or copper/cobalt oxide species, which were readily reducible at temperatures below 600°C. XPS analysis revealed that the surface of Mg-doped Ni-Co supported SiO2 catalysts was rich in nickel. All the prepared catalysts were active in CO2 hydrogenation to methane. The Mg-doped Ni-Co supported SiO2 catalysts showed higher catalytic activity compared to their Mg-doped Ni-Cu counterparts. The 1.5Mg10Ni5Co/SiO2 catalyst demonstrated 82% CO2 conversion and 99.5% selectivity to methane. The activity and selectivity of this catalyst was maintained at 400°C for a reaction time of 4h.

Enhanced CO2 Hydrogenation to Methanol Using out-of-Plane Grown MoS2 Flakes on Amorphous Carbon Scaffold.

The conversion of excess carbon dioxide (CO2) into valuable chemicals is critical for achieving a sustainable society. Among various catalysts, molybdenum disulfide (MoS2) has demonstrated potential for CO2 hydrogenation to methanol. However, its catalytic activity has yet to be fully optimized, and scalable, industrially viable production methods remain underdeveloped. In this work, a chemical vapor deposition (CVD) approach is introduced to grow vertically oriented MoS2 crystals on an amorphous carbon template. This method enhances the exposure of vacancy-rich basal planes, which are crucial for stable catalytic performance. The 2H-MoS2 flakes, supported on a conductive carbon scaffold, exhibit catalytic activity, achieving a net space-time yield of 2.68 gMeOH gcat⁻¹ h⁻¹ with a selectivity of 82.5% under mild conditions (264 °C, 10bar). This work highlights a significant step toward the industrial application of MoS2-based catalysts for CO2 conversion, bridging the gap between fundamental research and scalable implementation.

Ion Irradiation-Induced Coordinatively Unsaturated Zn Sites for Enhanced CO Hydrogenation.

Defect engineering critically influences metal oxide catalysis, yet controlling coordinatively unsaturated metal sites remains challenging due to their inherent instability under reaction conditions. Here, we demonstrate that high-flux argon ion (Ar+) irradiation above recrystallization temperatures generated well-defined coordinatively unsaturated Zn (CUZ) sites on ZnO(101̅0) surfaces that exhibited enhanced stability and activity for CO hydrogenation. Combining low-temperature scanning probe microscopy, ambient pressure X-ray photoelectron spectroscopy, and surface-ligand infrared spectroscopy with density functional theory calculations, we identified <12̅10> step edges exposing CUZ sites as the dominant active sites. These sites facilitate hydrogen-assisted CO dissociation through a mechanism distinct from formate-mediated pathways on stoichiometric ZnO. The ion-irradiation approach effectively addressed instability of Zn species, a major problem in ZnO catalysis, enabling stable performance in syngas conversion when combined with zeolites. Our atomic scale investigation provided spectroscopic fingerprints for active sites on the ZnO catalyst and insights into the structure-activity relationships of ZnO for CO hydrogenation. Our approach for engineering thermally stable defect sites in oxide catalysts provided opportunities for rational catalyst design beyond traditional preparation methods.

Confined Growth by Self-Combustion of a Cu-Based Nanophase into Mesostructured Acid Supports for DME Production from CO2.

This work deals with the design of nanocomposite hydrogenation-dehydration bifunctional catalysts for the one-pot conversion of CO2 to dimethyl ether (DME), focusing on obtaining a high and homogeneous dispersion of a Cu-based CO2 hydrogenation phase into the pores of mesostructured supports. Particularly, three aluminosilicate mesostructured acid catalysts with catalytic activity towards methanol dehydration and featuring different porous structures (Al-MCM-41, Al-SBA-15, Al-SBA-16) were synthesized and used as supports to host a CuO/ZnO/ZrO2 (CZZ) CO2 hydrogenation catalyst for methanol synthesis. The use of a mesostructured support allows to maximize the exposed surface of the CO2 reduction function by nanostructuring it through its confinement within the mesochannels, thus obtaining nanocomposite bifunctional catalysts with an ultra-small hydrogenation nanophase. The nanocomposites were obtained using an impregnation strategy combined with a self-combustion reaction, allowing to incorporate the CO2 reduction phase inside the mesopores. In all cases, the characterization shows that the hydrogenation phase species are highly and homogeneously dispersed into the supports as either small nanoparticles or as a nanolayer. The as-obtained nanocomposites were tested for their catalytic activity and the results discussed taking into account the structural, textural, and acidic properties of the supports and nanocomposites.

Unveiling the Role of Rhenium Precursors in Supercritical CO₂ Hydrogenation: A Comparative Study of ReOx/TiO₂ Catalysts

Heterogeneous rhenium catalysts supported on various oxides, particularly TiO2, have demonstrated effectiveness in converting carbon dioxide (CO2) to methanol via hydrogenation, showing high selectivity under diverse reaction conditions. However, the impact of different rhenium precursors on the catalytic performance and physicochemical properties of ReOx/TiO2 has not yet been elucidated. Herein, we compared catalysts prepared from NH4ReO4 and Re2O7 precursors with varying rhenium content (4 to 14 wt% Re) synthesized using a wet impregnation approach. These catalysts were evaluated under different reaction temperatures (200‐250 ºC), pressures (100‐200 bar), and H2/CO2 ratios (1‐4). This study revealed that both catalytic performance and physicochemical properties varied not only with the type of precursor but also with the rhenium content. Variation in reduction temperature, particle size, oxidation states of Re and surface Re=O terminals were observed. In batch system, catalysts derived from NH4ReO4 demonstrated a higher selectivity for methanol production under high pressure and stoichiometric conditions, regardless of temperature. In contrast, Re2O7‐based catalysts demonstrated higher methanol selectivity at 200°C, with H2/CO2 ratios between 1 and 3, regardless of the total pressure. These findings provide a deeper and valuable insight on the choice of precursors for the preparation of ReOx/TiO2 catalysts for CO2 hydrogenation.

Exceptional CO2 Hydrogenation to Ethanol via Precise Single-Atom Ir Deposition on Functional P Islands.

The thermocatalytic hydrogenation of CO2 to ethanol has attracted significant interest because ethanol offers ease of transport and substantial value in chemical synthesis. Here, we present a state-of-the-art catalyst for the CO2 hydrogenation to ethanol achieved by precisely depositing single-atom Ir species on P cluster islands situated on the In2O3 nanosheets. The Ir1-Px/In2O3 catalyst achieves an impressive ethanol yield of 3.33 mmol g-1 h-1 and a turnover frequency (TOF) of 914 h-1 under 1.0 MPa (H2/CO2=3 : 1) at 180 °C, nearly 8 times higher than that of the unmodified Ir1/In2O3 catalyst. Additionally, at a more industrially relevant pressure of 5.0 MPa, the TOF of the Ir1-Px/In2O3 catalyst can reach up to 2108 h-1, surpassing previously reported catalysts. Combined in situ characterization and theoretical studies reveal that the hydrogenation process is significantly enhanced by the Ir1-Px entities. Specifically, the Ir atom facilitates CO2 activation and C-C coupling, while the surrounding P island exhibits exceptional H2 dissociation ability. These three steps have been found crucial for the CO2 hydrogenation reaction. This discovery opens new opportunities for the regulation of the microenvironment of current catalysts by providing essential chemical functionalities that enhance intricate and complex reaction processes.

Exceptional CO2 Hydrogenation to Ethanol via Precise Single‐Atom Ir Deposition on Functional P Islands

AbstractThe thermocatalytic hydrogenation of CO2 to ethanol has attracted significant interest because ethanol offers ease of transport and substantial value in chemical synthesis. Here, we present a state‐of‐the‐art catalyst for the CO2 hydrogenation to ethanol achieved by precisely depositing single‐atom Ir species on P cluster islands situated on the In2O3 nanosheets. The Ir1‐Px/In2O3 catalyst achieves an impressive ethanol yield of 3.33 mmol g−1 h−1 and a turnover frequency (TOF) of 914 h−1 under 1.0 MPa (H2/CO2=3 : 1) at 180 °C, nearly 8 times higher than that of the unmodified Ir1/In2O3 catalyst. Additionally, at a more industrially relevant pressure of 5.0 MPa, the TOF of the Ir1‐Px/In2O3 catalyst can reach up to 2108 h−1, surpassing previously reported catalysts. Combined in situ characterization and theoretical studies reveal that the hydrogenation process is significantly enhanced by the Ir1‐Px entities. Specifically, the Ir atom facilitates CO2 activation and C−C coupling, while the surrounding P island exhibits exceptional H2 dissociation ability. These three steps have been found crucial for the CO2 hydrogenation reaction. This discovery opens new opportunities for the regulation of the microenvironment of current catalysts by providing essential chemical functionalities that enhance intricate and complex reaction processes.

Life-cycle assessment of oil recovery using dimethyl ether produced from green hydrogen and captured CO2

Hydrocarbon fuels are widely recognized as significant contributors to climate change and the rising levels of CO2 in the atmosphere. As a result, it is crucial to reduce the net carbon intensity of energy derived from these fuels. This study explores the feasibility of using dimethyl ether (DME), produced through the hydrogenation of CO2, as a low-carbon method for generating electricity from hydrocarbon fuels. The proposed approach involves capturing the emitted CO2 during combustion and utilizing it to produce the necessary DME in a closed cycle. It is shown that for a mature reservoir in the Middle East, this method can mitigate approximately 75% of the CO2 emissions released from burning the produced oil. By incorporating zero-carbon electricity throughout the process, the total abatement of CO2 can reach 85%. Furthermore, the study highlights the importance of improving the DME utilization factor (bbl-oil/tDME). By optimizing this factor, high abatement rates can be achieved. However, it is important to note that implementing this method comes with a high exergetic cost. During a certain period in the field’s lifetime, the invested energy exceeds the energy produced. The stages with the highest exergy consumption are CO2 capture and hydrogen production.

Effects of hydrogen spillover on CO2 hydrogenation over Pt-Co-Al based catalysts

Effects of hydrogen spillover on CO2 hydrogenation over Pt-Co-Al based catalysts

Green and more sustainable catalyst for CO and CO2 hydrogenation

Green and more sustainable catalyst for CO and CO2 hydrogenation

Design and numerical analysis of an offshore methanol synthesis process through CO2 hydrogenation

Design and numerical analysis of an offshore methanol synthesis process through CO2 hydrogenation

Unveiling the role of Ni nanometric particles in ultra-stable hierarchically porous Y zeolite to drive methane steam reforming and CO2 hydrogenation

Unveiling the role of Ni nanometric particles in ultra-stable hierarchically porous Y zeolite to drive methane steam reforming and CO2 hydrogenation

Process integration and life cycle assessment of ethane thermal cracking, carbon capture, green hydrogen, CO2 hydrogenation and methanol to olefins

Process integration and life cycle assessment of ethane thermal cracking, carbon capture, green hydrogen, CO2 hydrogenation and methanol to olefins

Improved CO selectivity during CO2 hydrogenation by bimetallic copper-cobalt supported SBA-15

Improved CO selectivity during CO2 hydrogenation by bimetallic copper-cobalt supported SBA-15

In-situ low-temperature CO2 mineralization and hydrogen tracing using ultramafic rocks from Australia and New Zealand

In-situ low-temperature CO2 mineralization and hydrogen tracing using ultramafic rocks from Australia and New Zealand

HF acid treatment induced nitrogen vacancies enriched g-C3N4 for efficient photocatalytic CO2 reduction and hydrogen production

HF acid treatment induced nitrogen vacancies enriched g-C3N4 for efficient photocatalytic CO2 reduction and hydrogen production

Recent Developments in Catalytic CO2‐to‐Ethanol Conversion Technologies

AbstractThis review provides a comprehensive overview of current progress in catalytic technologies for converting CO2 to ethanol, emphasizing the importance of sustainable and environmentally friendly alternatives. A range of methodologies is explored, including thermodynamic analysis, thermocatalytic, electrocatalytic, and photocatalytic approaches, while discussing fundamental reaction mechanisms and catalyst design strategies. Significant advancement has been made in the thermocatalytic hydrogenation of CO2, with mixed metal and metal oxide catalysts achieving selectivities exceeding 90%. However, challenges remain in optimizing catalyst performance for enhanced selectivity and conversion rates. Electrocatalytic reduction offers a promising pathway, focusing on alkaline electrolytes and innovative catalyst designs such as Cu/Au and Al‐Cu/Cu2O. Meanwhile, photocatalytic systems harness solar energy, with various novel photocatalysts showing potential for high efficiency. This review aims to elucidate the current landscape and future perspectives on CO2‐to‐ethanol conversion technologies, highlighting their potential role in sustainable energy solutions.

Application of moving-bed reactor for effective hydrogenation of CO2 captured with a dual-function material to enhance the concentration of the gaseous product of methane

Application of moving-bed reactor for effective hydrogenation of CO2 captured with a dual-function material to enhance the concentration of the gaseous product of methane