Surface Density Optimization of V-Zr Mixed Oxides Cografted on γ-Al₂O₃ Using OV(OⁱPr)₃ and Zr(OⁿBu)₄ Precursors

Abstract

Cografted catalysts are synthesized by reacting surface -OH groups of a catalyst support with a solution containing two or more metal precursors. Under these circumstances factors such as temperature, concentration of metal precursors, time of cografting, and variations in metal precursor feeds can affect the surface metal densities. To understand influence of these parameters a compositional range of V-Zr cografted catalysts were synthesized using OV(O ⁱ Pr)₃ and Zr(O ⁿ Bu)₄ and studied. These catalysts were then characterized using ICP-OES, XRD, and XPS. XRD revealed that cografting was amorphous and XPS studies indicated that V⁵⁺ and Zr⁴⁺ were the only species present under ambient conditions.

Keywords:

• cografting
• heterogeneous catalysis
• SOMC
• steam reforming
• surface organometallic chemistry
• supported metal oxides
• γ-alumina
• vanadium
• zirconium

Acknowledgments

The authors gratefully acknowledge the support of the Department of Chemistry, University of Iowa. The assistance of Dr. Dale Swenson, Dr. Sarah Larsen, and the staff at the Central Microscopic Facility at University of Iowa for equipment use is much appreciated.