Dandapat, Anirban and Jana, Debrina and De, Goutam (2009) Synthesis of Thick Mesoporous gamma-Alumina Films, Loading of Pt Nanoparticles, and Use of the Composite Film as a Reusable Catalyst. ACS Applied Materials & Interfaces, 1 (4). pp. 833-840. ISSN 1944-8244

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Abstract

Nanocrystalline mesoporous gamma-Al(2)O(3) film of high thickness has been developed and characterized. The films were prepared on ordinary glass substrates by a single dip-coating method using boehmite (AIOOH) sols derived from aluminum tri-sec-butoxide in presence of cetyltrimethylammonium bromide (CTAB) as structure-directing agent. The dried films were heat-created at 500 degrees C in air to remove the organics and strengthen the network. The GIXRD of the heat-treated (500 degrees C) film shows a broad peak in the low-angle region supporting the formation OF worm-hole-like disordered mesostructures. The high-angle GIXRD, FTIR, and TEM of the films confirm the formation of gamma-Al(2)O(3). N(2) adsorption-desorption analyses showed that the heat-treated (500 degrees C) film has a BET surface area of 171 m(2) g(-1) with a pore volume of 0.188 cm(3) g(-1) and mean pore diameter 4.3 nm. Pt nanoparticles (NPs) (similar to 2.7 mol % with respect to the equivalent AlO(1.5)) were generated inside the mesopores of the heat-treated films simply by soaking H(2)PtCl(6) solutions into it, and followed by thermal decomposition at 500 degrees C, The surface area and pore volume of the Pt-incorporated film have been reduced to 101 m(2) g(-1) and 0.119 cm(3) g(-1) respectively, confirming the inclusion OF Pt NPs inside the pores. FESEM and TEM studies revealed uniform distribution of Pt NPs (2-8.5 nm: average diameter 4.9 nm) in the films. Catalytic properties of the Pt-incorporated films were investigated in two model (one inorganic and other organic) systems: reduction of hexacyanoferrate(III) ions by thiosulfate to ferrocyanide, and p-nitrophenol to p-aminophenol. In both the cases, the catalyst showed excellent activities, and the reduction reactions followed smoothly, showing isosbestic points in the UV-visible spectra. The catalyst films can be separated easily after the reactions and reused several times.

Item Type:	Article
Uncontrolled Keywords:	Mesoporous gamma-Al(2)O(3) film; CTAB; Pt nanoparticles; Catalysis; reductions of hexacyanoferrate(III) and p-nitrophenol
Subjects:	Engineering Materials
Divisions:	UNSPECIFIED
Depositing User:	Ashok K Podder
Date Deposited:	22 Feb 2012 06:01
Last Modified:	22 Feb 2012 06:01
URI:	http://cgcri.csircentral.net/id/eprint/988

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