The Effect of pH and Metal Loading on the Properties of Sol-Gel Rh/SiO
Rh/SiO{sub 2}, to be used as a potential catalytic material, was prepared using sol-gel processing. Tetraethoxysilane (TEOS) was used as the support precursor and Rh(acac){sub 3} was used as the metal precursor. Nitrogen full-sorption was used to determine surface area, average pore size, and total pore volume of the support, while hydrogen chemisorption and electron microscopy were used to determine metal particle size. Samples prepared at a pH of about 3 had a high metal dispersion and well-defined pore size distribution. Designed metal loading was varied from 0.5 to 1.5 wt%. Dried gels were probed using {sup 29}Si Solid state MAS NMR, and the relative amount of partially and fully condensed (Q{sub 2}, Q{sub 3}, Q{sub 4}) silicon centers was quantified. As the metal loading was increased, the gels became more fully condensed. Silica prepared at a pH of about 8 showed a significant increase in the degree of condensation regardless of the rhodium content.
- Research Organization:
- Department of Chemical Engineering, Tulane University, New Orleans, Louisiana (US)
- Sponsoring Organization:
- USDOE Office of Science; Louisiana Board of Regents; National Science Foundation; Electron Microscope Laboratories of Louisiana State University School of Veterinary Medicine and Tulane University (US)
- OSTI ID:
- 785147
- Journal Information:
- Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 2 Vol. 158; ISSN 0022-4596; ISSN JSSCBI
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effect of support material on Rh catalysts
Effect of pH on the magnetic and dielectric properties of SiO{sub 2}/NiZn ferrite nanocomposites
Related Subjects
CATALYST SUPPORTS
CATALYSTS
CHEMICAL PREPARATION
CHEMISORPTION
EXPERIMENTAL DATA
LOADING RATE
NUCLEAR MAGNETIC RESONANCE
ORGANOMETALLIC COMPOUNDS
PH VALUE
PORE STRUCTURE
PRECURSOR
RHODIUM
RHODIUM COMPOUNDS
SILANES
SILICA
SILICON OXIDES
SOL-GEL PROCESS
SURFACE AREA
THERMAL GRAVIMETRIC ANALYSIS
TRANSMISSION ELECTRON MICROSCOPY