Gold nanoparticles stabilized by a flake-like Al2O3 support

Abstract

A flake-like alumina with rough surface and small mesopores has been prepared by a hydrothermal method. Remarkably, such alumina was able to stabilize Au nanoparticles, predominantly ∼2.2 nm in size, even up to an annealing temperature of 700°C. The catalytic activity was tested using the CO oxidation model reaction where a complete conversion of 1% CO in air at 30°C was obtained.

Alumina hollow microspheres supported gold catalysts for low-temperature CO oxidation: effect of the pretreatment atmospheres on the catalytic activity and stability

“…In addition, based on the best results from Fig. 2, the reactive rate at 30°C for the Au/ Al 2 O 3 -H 2 catalyst was calculated as 2.109 mol/h g Au , which is comparable and even higher than the results in the literature [19,[28][29][30] (Table 1).…”

“…Gold was deposited onto the surface of γ-Al 2 O 3 hollow microspheres by a deposition-precipitation (DP) method using (NH 4 ) 2 CO 3 as precipitant and HAuCl 4 solution (7.888 g/L) as the gold precursor, similar to the procedure used in our previous work [28]. In a typical preparation, HAuCl 4 was added dropwise to an aqueous suspension of Al 2 O 3 , and the pH of the suspension was adjusted to 8-9 by addition of 0.…”

“…One can see that the gold particle sizes of the used Au/Al 2 O 3 -H 2 catalyst (3.9±0.4 nm) are similar to those of the fresh sample (3.0±0.4 nm). The outstanding stability could be relating to the novel surface structure of our Al 2 O 3 support, which contributes to a solid stabilization of Au NPs [19,28].…”

A facile method for in situ growing nano-flaky γ-Al2O3 on the surface of Al–Si alloy sphere

“…Alumina is widely used as catalyst supports in industries due to its high surface area and abundant surface hydroxyl groups [13][14][15]. However, the low thermal conductivity limits its application in some strongly exothermic reactions in catalytic applications.…”

“…Up to now, many routes were provided to prepare the core-shell structured composite in the literatures, such as sol-gel process [5], homogenous precipitation method [6], layer-by-layer technique [7] and spray pyrolysis [8]. Beyond that, in situ growth, due to the high adhesion ability of the shell layer and core, has caught much attention [9][10][11][12].Alumina is widely used as catalyst supports in industries due to its high surface area and abundant surface hydroxyl groups [13][14][15]. However, the low thermal conductivity limits its application in some strongly exothermic reactions in catalytic applications.…”