Tao Keyi

Characterization and catalytic properties of supported nickel molybdenum nitrides for hydrodenitrogenation

Abstract The characterization and hydrodenitrogenation activity of 3-methyl pyridine have been obtained. The results from the characterization techniques (X-ray diffraction (XRD), temperature-programmed reaction (TPR) and XPS) were used to illustrate the structure, surface reduction properties and the role of Ni metal in the reaction. The NiMoN x /γ-Al 2 O 3 catalyst is more active than a Mo 2 N/γ-Al 2 O 3 catalyst with the same MoO 3 loading. Mo 2 N, Ni 3 Mo 3 N and Ni metal are formed in the NiMoN x /γ-Al 2 O 3 catalyst; moreover, the synergy among them is probably responsible for the high activity of NiMoN x /γ-Al 2 O 3 catalyst. The addition of Ni metal enhances the reducibility of Mo 2 N/γ-Al 2 O 3 phase and also promotes the HDN activity. The reasons for reduction before reaction and the surface ion state changes during reduction are illustrated by XPS techniques.

Advances in chemical synthesis and application of metal-metalloid amorphous alloy nanoparticulate catalysts

This paper reviews the advances in the chemical synthesis and application of metal-metalloid amorphous alloy nanoparticles consisting of transition metal (M) and metalloid elements (B, P). After a brief introduction on the history of amorphous alloy catalysts, the paper focuses on the properties and characterization of amorphous alloy catalysts, and recent developments in the solution-phase synthesis of amorphous alloy nanoparticles. This paper further outlines the applications of amorphous alloys, with special emphasis on the problems and strategies for the application of amorphous alloy nanoparticles in catalytic reactions.

Hydrogenation of furfuryl alcohol to tetrahydrofurfuryl alcohol on NiB/SiO2 amorphous alloy catalyst

NiB/SiO2 amorphous alloy catalyst was prepared by power electroless plating method and characterized by induction coupled plasma (ICP), Brunauer-Emmett-Teller method (BET), transmission electron microscope (TEM) and X-ray diffraction (XRD) techniques. The catalytic performance of NiB/SiO2 was investigated for the hydrogenation of furfuryl alcohol (FA) to tetrahydrofurfuryl alcohol (THFA). The effects of operational conditions, such as reaction temperature, pressure, and stirring rate were carefully studied. The proper conditions were determined as the following: pressure 2.0 MPa, temperature 120°C and stirring rate 550 r/min. A typical result with FA conversion of 99% and THFA selectivity of 100% was obtained under such conditions, which was close to that over Raney Ni.

Determination of arsenic, antimony, selenium and tin by atomic absorption spectroscopy using hydride generation and atomization under low pressure

Abstract A method has been developed for the determination of arsenic, antimony, selenium and tin by a vacuum flameless atomic absorption technique with hydride generation under subatmospheric pressure. The hydrides are generated by adding dilute (1% m/v) sodium borohydride solution to the acidified sample in a subatmospheric generator using a vacuum pump. The liberated hydrides are passed directly into an evacuated, heated quartz tube. The advantages of the proposed system are its simplicity, high sensitivity and high speed of analysis.

Preparation and Characterization of NiB Amorphous Alloy Modified Using Chitosan

NiB amorphous alloy catalyst (NiB-CS) was prepared by direct reduction using the chemical- reduction method with chitosan as a stabilizer. The amorphous structure, atomic composition, and particle size of the as-prepared catalysts were characterized by X-ray diffraction (XRD), inductively coupled plasma spectrometry (ICP), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). The catalytic behavior during the hydrogenation of furfuryl alcohol (FA) to tetrafurfural alcohol (THFA) was studied and compared with the NiB catalyst prepared without chitosan. The amorphous NiB-CS catalyst was found to be more reactive than the NiB catalyst. The superior catalytic activity of the NiB-CS catalyst is attributed to the small NiB particles and the high surface content of Ni active species. (Article)