Zoran Novak (Author), Petra Kotnik (Author), Željko Knez (Author)

Abstract

Single tungsten oxide aerogels (WO3), binary oxide aerogels (WO3-Al2O3) and ternary oxide aerogels (WO3-SiO2-Al2O3) were prepared using standard sol-gel route. Tungsten oxide tetraethoxide (WO(OCH2CH3)4) was used as the sol-gel precursor. The excellent properties of the gels obtained by the sol-gel synthesis were preserved upon supercritical drying with CO2. After supercritical drying at 40 °C and 100 bar, all aerogels were calcined to 800 °C. The influence of the synthesis parameters on the catalytic activity of WO3as supported on silica andžor alumina aerogels was investigated through thetransformation of N-(phosphonomethyl)iminodiacetic acid to N-(phosphonomethyl)glycine. Despite including WO3 into single and mixed silicaand alumina aerogels, high specific surface areas (284-653 m2 g-1) were preserved. Higher conversion was obtained for catalysts with higher ratios of WO3 in the mixed silica-alumina aerogels that were calcined at 800 °C.

Keywords

kemijska procesna tehnika;aerogeli;katalizatorji;volframovi oksidi;priprava aerogelov;karakterizacija aerogelov;superkritični CO2;superkritično sušenje;visokotlačna tehnologija;chemical processing;aerogels;catalysts;tungsten oxides;preparation of aerogels;characterisation of aerogels;supercritical CO2;supercritical drying;high pressure technology;

Data

Language: English
Year of publishing:
Typology: 1.01 - Original Scientific Article
Organization: UM FS - Faculty of Mechanical Engineering
UDC: 66-911.48:66-987
COBISS: 9330966 Link will open in a new window
ISSN: 0022-3093
Views: 1522
Downloads: 33
Average score: 0 (0 votes)
Metadata: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Other data

Secondary language: English
Secondary keywords: kemijska procesna tehnika;aerogeli;katalizatorji;volframovi oksidi;priprava aerogelov;karakterizacija aerogelov;superkritični CO2;superkritično sušenje;visokotlačna tehnologija;
URN: URN:SI:UM:
Pages: str. 308-313
Volume: ǂVol. ǂ350
Chronology: Dec. 2004
ID: 8718742