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The high concentration of CO bound in seawater represents a significant opportunity to extract and use this CO as a C feedstock for synthetic fuels. Using an existing process, CO and H can be concurrently extracted from seawater and then catalytically reacted to produce synthetic fuel. Hydrogenating CO directly into liquid hydrocarbons is exceptionally difficult, but by first identifying a catalyst for selective CO production through the reverse water-gas shift (RWGS) reaction, CO can then be hydrogenated to fuel through Fischer-Tropsch (FT) synthesis. Results of this study demonstrate that potassium-promoted molybdenum carbide supported on γ-Al O (K-Mo C/γ-Al O ) is a low-cost, stable, and highly selective catalyst for RWGS over a wide range of conversions. These findings are supported by X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and density functional theory calculations.

Revealed linear relationships between oxygen coverage and electronic modification of the Mo2C catalyst that tunes the reactivity for CO2 reduction.

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To study the effects of different oxygen functional groups on the quality of flotation clean low-rank coal, two kinds of collectors with different oxygen-containing functional groups, methyl laurate, and dodecanol, were selected and their flotation behaviors were investigated. The Bulianta coal was the typical sub-bituminous coal in China, and the coal molecular model of which was constructed based on proximate analysis, ultimate analysis, 13C-NMR, and XPS. The chemical structure model of the coal molecule was optimized, and the periodic boundary condition was added via the method of molecular dynamics methods. The different combined systems formed by collectors, water, and a model surface of Bulianta coal have been studied using molecular dynamics simulation. The simulation results of dodecanol and methyl laurate on the surface of Bulianta coal show that dodecanol molecules are not evenly adsorbed on the surface of coal, and have higher adsorption capacity near carboxyl and hydroxyl groups, but less adsorption capacity near carbonyl and ether bonds. Methyl laurate can completely cover the oxygen-containing functional groups on the coal surface. Compared with dodecanol, methyl laurate can effectively improve the hydrophobicity of the Bulianta coal surface, which is consistent with the results of the XPS test and the flotation test.

Coal is often coated by kaolinite in flotation, leading to a decrease in the quality of clean coal. The structure of the mineral determines its properties and flotation behavior. Therefore, to remove the kaolinite from coal efficiently, the difference in mineralogical characteristics between non-coal and coal kaolinite were analyzed using advanced instruments. The experiment results showed that, due to the substitution of the C atom for Si atom, the interplanar spacing of the kaolinite (001) surface became small with C-O-C, Al-O-C, and C-O-Si covalent bonds formed instead of Al-O-Si and Si-O-Si bond. Based on this, the models of monolayer and bilayer coal kaolinite (001) surfaces were built and the structure difference was compared through DFT calculation. The calculation results showed that the silicon atom of the kaolinite Si-O-(001) surface was easier to be doped by carbon atoms with external energy as the interplanar spacing of the kaolinite (001) surface decreased with the increase in doped carbon atoms (7.15440 Å→7.11859 Å→7.10902 Å→7.10105 Å). The structural difference between non-coal kaolinite and coal kaolinite were compared from the view of the experiment and quantum chemistry, which provides an important theory for subsequent research on the properties of coal kaolinite and its further processing and utilization.

To investigate the effect of carbon defects on the hydrophilicity of the whole surface of the coal pyrite, the adsorption of the single H2O molecule at different sites of the coal pyrite surface was studied with the DFT calculation. It was found that, like the ideal pyrite, the single H2O molecule can stably adsorb at the doping-position, the ortho-position and the meta-position of the coal pyrite. The covalent bond and anti-bond were formed between O (water molecule) and Fe (the coal pyrite) through the Fe 3d orbital and O 2p orbital. Meanwhile, the S–H bond was replaced by the C–H bond. But away from the carbon defect centre, the adsorption of the single H2O molecule increased gradually and the Fe–O covalent bond strength between the single H2O molecule and the pyrite strengthened, which eventually became close to that of the undoped coal pyrite surface.