Porous hierarchical nickel nanostructures and their application as a magnetically separable catalyst

Abstract

A convenient template-and surfactant-free strategy has been developed to prepare porous hierarchical Ni nanostructures by directly calcining the nickel-based flower-like precursor in Ar. The precursor is preformed by refluxing the solution of nickel nitrate and the co-precipitators of hexamethylenetetramine and oxalic acid at 100 C for 6 h. The unique Ni nanostructures are composed of porous sheets of several nanometers in thickness with a wide pore size distribution of 5-100 nm, with a Brunauer-Emmett-Teller specific surface area up to 24.5 m 2 g À1 . The formation process has been in situ examined by thermogravimetry-differential scanning calorimetry-mass spectroscopy, which illuminates the continuous generation of Ni species with the simultaneous release of gaseous species from decomposition and/or reduction of the precursor. Coupled with the good soft ferromagnetism, the porous Ni nanostructures with high surface area have great potential as a magnetically separable catalyst, as demonstrated in the excellent performance for the selective hydrogenation of acetophenone to 1-phenylethanol at 100 C.

A facile large-scale synthesis and luminescence properties of Gd2O3:Eu3+ nanoflowers

“…1(f-h). This kind of porous structures can be formed due to the dehydration and decomposition of Gd(OH) 3 during the annealing process [11][12][13]. The fabricated porous nanomaterials have great potential in the fields of catalysis, sensing, and energy storage.…”

A novel Fe3O4@nSiO2@NiPd–PVP@mSiO2 multi-shell core–shell nanocomposite for cinnamic acid hydrogenation in water

“…1,2 The design and preparation of high efficient catalysts play a key role in this transformation. 9,10 For example, Wu et al have prepared a hierarchical porous Ni-based catalyst by calcining the nickel precursor in Ar, which showed good catalytic performance in the selective hydrogenation of acetophenone to 1-phenylethanol. [3][4][5][6][7][8][9][10][11] Most of the catalysts used in catalytic hydrogenation were noble metal catalysts, including Au, 4 Ru, 5 Pt, 6 Pd 7 based catalysts, and have achieved good results.…”

“…Particularly, nano catalysts have been widely applied in catalytic hydrogenation owing to their small particle size, high surface area and extraordinary catalytic properties. 9 Unfortunately, these nano catalysts usually tended to aggregate and were difficult to be separated effectively from the reaction systems by the traditional methods, such as filtration and centrifugalization, due to their high surface energies and small sizes. However, the high price of noble metals limited further applications of such catalysts in industry.…”

Highly dispersed Ni nanoparticles on mesoporous silica nanospheres by melt infiltration for transfer hydrogenation of aryl ketones

“…5 Among the catalysts for TH reactions, nickel-based catalysts are representative, due to the metallic nickel surface can absorbs hydrogen and easily activates hydrogen in the atomic state. [6][7][8][9][10][11] In addition, nickel compounds could be the signicant catalyst candidate because of the low price, accessibility, and high reactivity. 12,13 Therefore, several works used nickel nanocatalysts for TH reactions.…”

“…It exhibits higher TON compared to other heterogeneous nickel nanocatalysts including our previous article. 6,15,35 The optimized conditions were applied to extend the scope.…”