Yue An

Nickel–platinum nanoparticles immobilized on graphitic carbon nitride as highly efficient catalyst for hydrogen release from hydrous hydrazine

Here we demonstrate that the combination of NiPt alloy nanoparticles with a graphitic carbon nitride (g-C3N4) support facilitates H2 production from hydrous hydrazine in an alkaline solution under moderate conditions. Of all the heterogeneous catalysts tested, Ni37Pt63/g-C3N4 shows superior catalytic performance with a maximum initial turnover frequency (TOF) of 570 h−1 at 323 K.

Efficient hydrogen generation from formic acid using AgPd nanoparticles immobilized on carbon nitride-functionalized SBA-15

Bimetallic AgPd nanoparticles were successfully immobilized on graphitic carbon nitride (g-C3N4) functionalized SBA-15 for the first time by a facile co-reduction method. These catalysts were applied in the decomposition of formic acid. The dehydrogenation of formic acid is dependent on the composition of AgPd and the content of carbon nitride (CN). Among all of the AgPd/mCND/SBA-15 catalysts tested, the Ag10Pd90/0.2CND/SBA-15 catalyst exhibits highly superior performance for the decomposition of formic acid into high-quality hydrogen at 323 K with 100% hydrogen selectivity and a turnover frequency of 893 h−1, which is among the maximum values obtained at 323 K in this paper. The improved performance is a promising step towards the utilization of formic acid as a hydrogen storage material.

Facile synthesis of amine-functionalized SBA-15-supported bimetallic Au–Pd nanoparticles as an efficient catalyst for hydrogen generation from formic acid

In this study, a series of amine-functionalized SBA-15-supported bimetallic Au–Pd nanoparticles (Au–Pd/SBA-15-Amine) as catalysts are successfully synthesized by surface functionalization and co-reduction and characterized by inductively coupled plasma-atomic emission spectroscopy, XRD, XPS, and TEM. The Au–Pd/SBA-15-Amine catalysts thus obtained are tested for the dehydrogenation of formic acid (FA)–sodium formate (SF). Among the tested Au–Pd/SBA-15-Amine catalysts, as-synthesized Au2Pd8/SBA-15-Amine exhibits 100% H2 selectivity and outstanding catalytic activity with an initial turnover frequency (TOF) of 1786 h−1 at 323 K; this superior catalytic activity is attributed to synergy between Au–Pd and SBA-15-Amine and the promotion effect of SF. At SF concentrations of greater than 0.5 mol L−1, SF can partially participate in dehydrogenation. The facile synthesis of the Au–Pd/SBA-15-Amine catalyst is imperative for accelerating the widespread application of FA–SF mixtures as a promising hydrogen carrier.

Hydrogen absorption properties of the slurry system composed of liquid C6H6 and F-treated Mg2Ni

Abstract The hydrogenation characteristics of the slurry composed of the NH 4 F solution treated Mg 2 Ni and liquid C 6 H 6 were studied. The F-treatment results in a net-shaped MgF 2 surface and higher nickel content in the sub-layer. It is found that the hydride of the NH 4 F treated alloy has a much higher activity for the hydrogenation of benzene. The catalytic activity for hydrogenation of the alloy depended strongly on the surface properties of the catalyst. At 483 K and under a hydrogen pressure of 4.0 MPa, the alloy absorbed hydrogen first, transformed into hydride and then the benzene was hydrogenated to cyclohexane with the hydride as the catalyst. The hydrogen absorption capacity of slurry system composed of 20 wt.% treated alloy and benzene reached ∼6.4 wt.% and the hydrogenation completed in ∼20 min. Results of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) analysis on the crystal structure, surface composition and surface morphology of the untreated and treated alloy are presented and discussed.

Hydrogen absorption properties of a slurry system composed of a magnesium alloy powder and C6H6

Abstract The hydrogen absorption properties of slurries composed of La 1.8 Ca 0.2 Mg 17− x Ni x alloy powder suspended in liquid C 6 H 6 were investigated. It is found that the La 1.8 Ca 0.2 Mg 14 Ni 3 in benzene liquid has similar hydrogen absorption properties as that of the hydrogen-alloy (gas–solid) reaction and the alloy has a strong catalytic effect on hydrogenation reaction of C 6 H 6 . The amount of hydrogen absorbed and the hydriding kinetics are related to the temperature, the solid/liquid weight ratio and the surface catalytic activity of the alloy. When the temperature of the slurry is ∼473 K, it acquires a good hydriding rate. The hydrogen absorption capacity of the slurry system composed of 50 wt.% La 1.8 Ca 0.2 Mg 14 Ni 3 alloy and 50 wt.% C 6 H 6 reaches 5.5 wt.% of hydrogen at 483 K and 4.5 MPa in 240 min. Results of XRD, XPS and SEM analysis on the crystal structure, surface structure and configuration of the alloy correlated with its catalytic activity are reported and discussed.

Biosynthesized Au/TiO2@SBA-15 catalysts for selective oxidation of cyclohexane with O2

A variety of TiO2@SBA-15 supporters with various TiO2 loadings were synthesized using a facile sol-gel method. Gold (Au)-based catalysts were prepared with an environmentally benign and economical bioreduction method via Cacumen Platycladi (CP) leaf extract and immobilized on various TiO2@SBA-15 supporters with different TiO2 loadings. The as-prepared biosynthesized Au catalysts were applied in the liquid-phase cyclohexane oxidation. The results showed that the Au nanoparticles were well-dispersed on TiO2@SBA-15, and the Au existed as Au0. These biosynthesized Au catalysts are promising for cyclohexane oxidation, achieving a turnover frequency up to 3,426 h−1 with a 14.1% cyclohexane conversion rate.