CO2 hydrogenation to methane over mesoporous Co/SiO2 catalysts: Effect of structure

Bimetallic Metal-Organic Framework Derived Nanocatalyst for CO2 Fixation through Benzimidazole Formation and Methanation of CO2

In this paper, a bimetallic Metal-Organic Framework (MOF) CoNiBTC was employed as a precursor for the fabrication of bimetallic nanoalloys CoNi@C evenly disseminated in carbon shells. These functional nanomaterials are characterized by powdered X-ray diffraction (PXRD), Fourier Transform Infra-Red spectroscopy (FTIR), surface area porosity analyzer, X-ray photoelectron spectroscopy (XPS), Field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM), Hydrogen Temperature-Programmed Reduction (H2 TPR), CO2 Temperature-Programmed Desorption (CO2-TPD), and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). This nanocatalyst was utilized in the synthesis of benzimidazole from o-phenylenediamine in the presence of CO2 and H2 in a good yield of 81%. The catalyst was also efficient in the manufacture of several substituted benzimidazoles with high yield. Due to the existence of a bimetallic nanoalloy of Co and Ni, this catalyst was also employed in the methanation of CO2 with high selectivity (99.7%).

Effect of La on the catalytic performance of mesoporous Ni/γ-Al2O3 catalysts for dry reforming of methane

Mesoporous Ni/La2O3/γ-Al2O3 catalysts with different La contents (0, 0.5, 1.5, 2.5, 3.5, and 4.5 wt.%) were prepared by the step-by-step impregnation method. The physicochemical properties of the prepared Ni/La2O3/γ-Al2O3 catalysts were characterized by H2-TPR, XRD, BET, O2-TPO, and TG. The effect of La dosage on the catalytic performance of Ni/γ-Al2O3 catalyst for dry reforming of methane was further investigated. The results show that the La content has a significant effect on the reducibility of high-valence Ni species, specific surface area, pore size, and pore volume as well as the catalytic performances. The high-valence Ni species in the NL3.5A catalyst precursor has high reducibility. And the specific surface area, pore size and pore volume of the NL3.5A catalyst are 145.9 m2 g−1, 11.7 nm, and 0.47 cm3 g−1, respectively. The catalytic activity of the series of prepared mesoporous Ni/La2O3/γ-Al2O3 catalysts follows the order: NL3.5A > NL2.5A > NL4.5A > NL1.5A > NL0.5A > NL0A. Namely, the NL3.5A catalyst possesses the best catalytic activity. The CH4 and CO2 conversions of NL3.5A catalyst are 61.6 and 39.1% at 600 °C, respectively. Additionally, it maintains a superior recycle capability for dry reforming of methane reaction because of the high coke resistance compared with the Ni/γ-Al2O3 catalyst.

Hydrogenation of carbon dioxide (CO2) to fuels in microreactors: a review of set-ups and value-added chemicals production

A review of CO2 hydrogenation to fuels and value-added chemicals in microreactors.

CoCe/N–C hybrids constructed via Ce–O–Co solid solution for the deoxygenation of sulfoxide

CeO2-promoted Co–N–C hybrids were prepared by the strategy of solid solution construction for the deoxygenation of sulfoxide.

CO2 utilization by dry reforming of CH4 over mesoporous Ni/KIT-6 catalyst

The mesoporous Ni/KIT-6 catalysts with different composition were prepared by altering reduction temperatures. In addition, their physicochemical properties were characterized by X-ray diffraction, in-situ X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller techniques. The results shown that the specific surface area, composition and metallic Ni crystallinity of the Ni/KIT-6 catalyst were significantly affected by reduction temperatures. The catalytic performances of the prepared Ni/KIT-6 catalysts were evaluated via the CO2 reforming of CH4 into syngas and followed the order: RT0 < RT250 < RT300 < RT350 < RT400 < RT450 ≈ RT500. The specific surface area, pore volume, pore diameter, and Ni0 content of the most representative RT450 catalyst among of them were 646.7 m2 g−1, 0.92 cm3 g−1, 6.5 nm, and 30.9%, respectively. The CH4 and CO2 conversions of RT450 catalyst reached to 69.0 and 39.4% under a reaction temperature of 600 °C, respectively. The CO selectivity was greater than 49% and the RT450 catalyst had good stability.

CO2 Hydrogenation over Nanoceria-Supported Transition Metal Catalysts: Role of Ceria Morphology (Nanorods versus Nanocubes) and Active Phase Nature (Co versus Cu)

In this work we report on the combined impact of active phase nature (M: Co or Cu) and ceria nanoparticles support morphology (nanorods (NR) or nanocubes (NC)) on the physicochemical characteristics and CO2 hydrogenation performance of M/CeO2 composites at atmospheric pressure. It was found that CO2 conversion followed the order: Co/CeO2 > Cu/CeO2 > CeO2, independently of the support morphology. Co/CeO2 catalysts demonstrated the highest CO2 conversion (92% at 450 °C), accompanied by 93% CH4 selectivity. On the other hand, Cu/CeO2 samples were very selective for CO production, exhibiting 52% CO2 conversion and 95% CO selectivity at 380 °C. The results obtained in a wide range of H2:CO2 ratios (1-9) and temperatures (200-500 °C) are reaching in both cases the corresponding thermodynamic equilibrium conversions, revealing the superiority of Co- and Cu-based samples in methanation and reverse water-gas shift (rWGS) reactions, respectively. Moreover, samples supported on ceria nanocubes exhibited higher specific activity (µmol CO2·m-2·s-1) compared to samples of rod-like shape, disclosing the significant role of support morphology, besides that of metal nature (Co or Cu). Results are interpreted on the basis of different textural and redox properties of as-prepared samples in conjunction to the different impact of metal entity (Co or Cu) on CO2 hydrogenation process.

Hydrogenation of Carbon Dioxide to Value-Added Chemicals by Heterogeneous Catalysis and Plasma Catalysis

Due to the increasing emission of carbon dioxide (CO2), greenhouse effects are becoming more and more severe, causing global climate change. The conversion and utilization of CO2 is one of the possible solutions to reduce CO2 concentrations. This can be accomplished, among other methods, by direct hydrogenation of CO2, producing value-added products. In this review, the progress of mainly the last five years in direct hydrogenation of CO2 to value-added chemicals (e.g., CO, CH4, CH3OH, DME, olefins, and higher hydrocarbons) by heterogeneous catalysis and plasma catalysis is summarized, and research priorities for CO2 hydrogenation are proposed.