Aldol condensation reactions of acetone over alkali-modified vanadium phosphate catalysts

L Thomas, R Tanner, P Gill, R Wells, J E Bailie, G Kelly, S D Jackson, G Hutchings

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

The acid base properties of vanadium phosphate catalysts are investigated using the aldol condensation of acetone and the reactions of 2-methylbut-3-yn-2-ol (MBOH) over alkali-doped vanadium phosphate catalysts. Two well defined vanadium phosphates were investigated, namely (VO)(2)P2O7 and delta-VOPO4. Alkali-doped (VO)(2)P2O7 was prepared by heating alkali-doped VOHPO4.0.5H(2)O in He(8 h, 750degreesC), and Na+-, K+- and Cs+- doped samples were investigated. The reaction of MBOH was used to probe the acid base nature of the surface sites. The undoped V4+ (VO)(2)P2O7 exhibited only acidic active sites, whereas when doped with 10% Na+, K+ or Cs+ the active sites became predominantly basic in nature. Both the doped and undoped samples were selective for the formation of isophorone ( selectivity greater than or equal to90%) from the aldol condensation of acetone, and the Cs-doped and undoped (VO)(2)P2O7 exhibited similar intrinsic activities (mol(isophorone) m(-2) h(-1)). In contrast, alkali-doping of the V5+ vanadium phosphate gamma-VOPO4 did not induce the formation of a significant number of surface basic sites and the active sites for MBOH decomposition remained predominantly acidic in nature. Both the doped and undoped delta-VOPO4 were non- selective in the aldol condensation of acetone, and during the short-lived reaction, only hydrocarbons (typically isobutane and isobutene) were observed. The results are discussed with respect to the nature of active sites for the selective oxidation of n-butane to maleic anhydride.

Original languageEnglish
Pages (from-to)4555-4560
Number of pages6
JournalPhysical Chemistry Chemical Physics
Volume4
DOIs
Publication statusPublished - 2002

Keywords

  • VAPOR-PHASE CONDENSATION
  • HYDROTALCITE CATALYSTS
  • METHYL-METHACRYLATE
  • RECENT PROGRESS
  • BASE CATALYSTS
  • METHYLBUTYNOL
  • TECHNOLOGY
  • OLIGOMERIZATION
  • ACETALDEHYDE
  • BASICITY

Cite this

Aldol condensation reactions of acetone over alkali-modified vanadium phosphate catalysts. / Thomas, L ; Tanner, R ; Gill, P ; Wells, R ; Bailie, J E ; Kelly, G ; Jackson, S D ; Hutchings, G .

In: Physical Chemistry Chemical Physics, Vol. 4, 2002, p. 4555-4560.

Research output: Contribution to journalArticle

Thomas, L, Tanner, R, Gill, P, Wells, R, Bailie, JE, Kelly, G, Jackson, SD & Hutchings, G 2002, 'Aldol condensation reactions of acetone over alkali-modified vanadium phosphate catalysts', Physical Chemistry Chemical Physics, vol. 4, pp. 4555-4560. https://doi.org/10.1039/b204684a
Thomas, L ; Tanner, R ; Gill, P ; Wells, R ; Bailie, J E ; Kelly, G ; Jackson, S D ; Hutchings, G . / Aldol condensation reactions of acetone over alkali-modified vanadium phosphate catalysts. In: Physical Chemistry Chemical Physics. 2002 ; Vol. 4. pp. 4555-4560.
@article{c42c938b97024970b3ab68c19a07ce8d,
title = "Aldol condensation reactions of acetone over alkali-modified vanadium phosphate catalysts",
abstract = "The acid base properties of vanadium phosphate catalysts are investigated using the aldol condensation of acetone and the reactions of 2-methylbut-3-yn-2-ol (MBOH) over alkali-doped vanadium phosphate catalysts. Two well defined vanadium phosphates were investigated, namely (VO)(2)P2O7 and delta-VOPO4. Alkali-doped (VO)(2)P2O7 was prepared by heating alkali-doped VOHPO4.0.5H(2)O in He(8 h, 750degreesC), and Na+-, K+- and Cs+- doped samples were investigated. The reaction of MBOH was used to probe the acid base nature of the surface sites. The undoped V4+ (VO)(2)P2O7 exhibited only acidic active sites, whereas when doped with 10{\%} Na+, K+ or Cs+ the active sites became predominantly basic in nature. Both the doped and undoped samples were selective for the formation of isophorone ( selectivity greater than or equal to90{\%}) from the aldol condensation of acetone, and the Cs-doped and undoped (VO)(2)P2O7 exhibited similar intrinsic activities (mol(isophorone) m(-2) h(-1)). In contrast, alkali-doping of the V5+ vanadium phosphate gamma-VOPO4 did not induce the formation of a significant number of surface basic sites and the active sites for MBOH decomposition remained predominantly acidic in nature. Both the doped and undoped delta-VOPO4 were non- selective in the aldol condensation of acetone, and during the short-lived reaction, only hydrocarbons (typically isobutane and isobutene) were observed. The results are discussed with respect to the nature of active sites for the selective oxidation of n-butane to maleic anhydride.",
keywords = "VAPOR-PHASE CONDENSATION, HYDROTALCITE CATALYSTS, METHYL-METHACRYLATE, RECENT PROGRESS, BASE CATALYSTS, METHYLBUTYNOL, TECHNOLOGY, OLIGOMERIZATION, ACETALDEHYDE, BASICITY",
author = "L Thomas and R Tanner and P Gill and R Wells and Bailie, {J E} and G Kelly and Jackson, {S D} and G Hutchings",
year = "2002",
doi = "10.1039/b204684a",
language = "English",
volume = "4",
pages = "4555--4560",
journal = "Physical Chemistry Chemical Physics",
issn = "1463-9076",
publisher = "ROYAL SOC CHEMISTRY",

}

TY - JOUR

T1 - Aldol condensation reactions of acetone over alkali-modified vanadium phosphate catalysts

AU - Thomas, L

AU - Tanner, R

AU - Gill, P

AU - Wells, R

AU - Bailie, J E

AU - Kelly, G

AU - Jackson, S D

AU - Hutchings, G

PY - 2002

Y1 - 2002

N2 - The acid base properties of vanadium phosphate catalysts are investigated using the aldol condensation of acetone and the reactions of 2-methylbut-3-yn-2-ol (MBOH) over alkali-doped vanadium phosphate catalysts. Two well defined vanadium phosphates were investigated, namely (VO)(2)P2O7 and delta-VOPO4. Alkali-doped (VO)(2)P2O7 was prepared by heating alkali-doped VOHPO4.0.5H(2)O in He(8 h, 750degreesC), and Na+-, K+- and Cs+- doped samples were investigated. The reaction of MBOH was used to probe the acid base nature of the surface sites. The undoped V4+ (VO)(2)P2O7 exhibited only acidic active sites, whereas when doped with 10% Na+, K+ or Cs+ the active sites became predominantly basic in nature. Both the doped and undoped samples were selective for the formation of isophorone ( selectivity greater than or equal to90%) from the aldol condensation of acetone, and the Cs-doped and undoped (VO)(2)P2O7 exhibited similar intrinsic activities (mol(isophorone) m(-2) h(-1)). In contrast, alkali-doping of the V5+ vanadium phosphate gamma-VOPO4 did not induce the formation of a significant number of surface basic sites and the active sites for MBOH decomposition remained predominantly acidic in nature. Both the doped and undoped delta-VOPO4 were non- selective in the aldol condensation of acetone, and during the short-lived reaction, only hydrocarbons (typically isobutane and isobutene) were observed. The results are discussed with respect to the nature of active sites for the selective oxidation of n-butane to maleic anhydride.

AB - The acid base properties of vanadium phosphate catalysts are investigated using the aldol condensation of acetone and the reactions of 2-methylbut-3-yn-2-ol (MBOH) over alkali-doped vanadium phosphate catalysts. Two well defined vanadium phosphates were investigated, namely (VO)(2)P2O7 and delta-VOPO4. Alkali-doped (VO)(2)P2O7 was prepared by heating alkali-doped VOHPO4.0.5H(2)O in He(8 h, 750degreesC), and Na+-, K+- and Cs+- doped samples were investigated. The reaction of MBOH was used to probe the acid base nature of the surface sites. The undoped V4+ (VO)(2)P2O7 exhibited only acidic active sites, whereas when doped with 10% Na+, K+ or Cs+ the active sites became predominantly basic in nature. Both the doped and undoped samples were selective for the formation of isophorone ( selectivity greater than or equal to90%) from the aldol condensation of acetone, and the Cs-doped and undoped (VO)(2)P2O7 exhibited similar intrinsic activities (mol(isophorone) m(-2) h(-1)). In contrast, alkali-doping of the V5+ vanadium phosphate gamma-VOPO4 did not induce the formation of a significant number of surface basic sites and the active sites for MBOH decomposition remained predominantly acidic in nature. Both the doped and undoped delta-VOPO4 were non- selective in the aldol condensation of acetone, and during the short-lived reaction, only hydrocarbons (typically isobutane and isobutene) were observed. The results are discussed with respect to the nature of active sites for the selective oxidation of n-butane to maleic anhydride.

KW - VAPOR-PHASE CONDENSATION

KW - HYDROTALCITE CATALYSTS

KW - METHYL-METHACRYLATE

KW - RECENT PROGRESS

KW - BASE CATALYSTS

KW - METHYLBUTYNOL

KW - TECHNOLOGY

KW - OLIGOMERIZATION

KW - ACETALDEHYDE

KW - BASICITY

U2 - 10.1039/b204684a

DO - 10.1039/b204684a

M3 - Article

VL - 4

SP - 4555

EP - 4560

JO - Physical Chemistry Chemical Physics

JF - Physical Chemistry Chemical Physics

SN - 1463-9076

ER -