Xiamen University

About: Xiamen University is a education organization based out in Amoy, Fujian, China. It is known for research contribution in the topics: Catalysis & Population. The organization has 50472 authors who have published 54480 publications receiving 1058239 citations. The organization is also known as: Amoy University & Xiàmén Dàxué.

3D hierarchical porous amidoxime fibers speed up uranium extraction from seawater

Abstract: The development of amidoxime-based polymeric (ABP) fibers offers a solution for uranium extraction from seawater (UES) and provides an alternative solution to the uranium resource shortage. However, ABP adsorbents prepared by existing methods cannot meet the requirements of high adsorption capacity, high selectivity, good mechanical strength and long service life. Herein, we fabricated a 3D hierarchical porous, high specific surface area ABP (H-ABP) fiber via self-assembly of axial grafting chains. A high adsorption capacity of 11.50 mg-U per g-adsorbents was achieved in natural seawater, which is a significant breakthrough in UES. Meanwhile, the adsorption capacity of uranium was higher than its major competing element vanadium, which overturned the U/V mass ratio of the ABP fiber. The H-ABP fiber also exhibited good mechanical strength and a long service life of at least 10 adsorption–desorption cycles. The well-designed structure resulted in groundbreaking properties, which completely meet the requirements for the economic evaluation of UES. This work presents a new technology for the synthesis of highly efficient adsorbents for UES, thus opening a whole new means of nuclear fuel production from the ocean.

Impact of Hydrogenolysis on the Selectivity of the Fischer–Tropsch Synthesis: Diesel Fuel Production over Mesoporous Zeolite-Y-Supported Cobalt Nanoparticles

Abstract: Selectivity control is a challenging goal in Fischer–Tropsch (FT) synthesis. Hydrogenolysis is known to occur during FT synthesis, but its impact on product selectivity has been overlooked. Demonstrated herein is that effective control of hydrogenolysis by using mesoporous zeolite Y-supported cobalt nanoparticles can enhance the diesel fuel selectivity while keeping methane selectivity low. The sizes of the cobalt particles and mesopores are key factors which determine the selectivity both in FT synthesis and in hydrogenolysis of n-hexadecane, a model compound of heavier hydrocarbons. The diesel fuel selectivity in FT synthesis can reach 60 % with a CH4 selectivity of 5 % over a Na-type mesoporous Y-supported cobalt catalyst with medium mean sizes of 8.4 nm (Co particles) and 15 nm (mesopores). These findings offer a new strategy to tune the product selectivity and possible interpretations of the effect of cobalt particle size and the effect of support pore size in FT synthesis.

Comparative study of inhibition effects of benzotriazole for metals in neutral solutions as observed with surface-enhanced Raman spectroscopy

Abstract: Surface-enhanced Raman spectroscopy has been successfully extended to the study of corrosion inhibition of bare iron and nickel metals. The inhibition effects of benzotriazole (BTAH) for copper, iron, and nickel electrodes in 0.1 M KCl solution were investigated by using both polarization curves and in situ Raman techniques. The protective films formed on copper and iron surfaces, in the presence of BTAH, are characterized as [CuIBTA]n and [FeII(BTA)2]n, respectively. The formation of Fe−N coordinated bonds and the deprotonation of the triazole ring may occur while BTAH interacts with the iron surface. On the contrary, BTAH may interact with the nickel surface as neutral molecules in the whole potential range investigated resulting in a poor inhibition effect. The surface complex is characterized as [Ni−BTAH]. The potential dependence of the Raman spectra on copper and iron shows that the BTA- ion in the surface complex may rebind with H+ at more negative potentials and accordingly the inhibition efficien...