Aerobic oxidation of benzyl alcohols to benzaldehydes using monoclinic bismuth vanadate nanoparticles under visible light irradiation: Photocatalysis selectivity and inhibition

TY - JOUR

T1 - Aerobic oxidation of benzyl alcohols to benzaldehydes using monoclinic bismuth vanadate nanoparticles under visible light irradiation

T2 - Photocatalysis selectivity and inhibition

AU - Unsworth, Christopher A.

AU - Coulson, Ben

AU - Chechik, Victor

AU - Douthwaite, Richard E.

N1 - © 2017 Elsevier Inc. All rights reserved.This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy.

PY - 2017/10/1

Y1 - 2017/10/1

N2 - Monoclinic bismuth vanadate nanoparticles (nan-BiVO4) have been used for the selective photo-oxidation of benzyl alcohols (13 examples) to benzaldehydes under visible light irradiation using dioxygen as oxidant. Illumination with a blue LED (λmax = 470 nm) gave yields more than 30 times greater than bulk BiVO4 with >99% selectivity for several cases. Photo-oxidation of PhCH2OH/PhCD2OH isotopomers gave a kinetic isotope effect of 1.3 indicating that C–H bond activation is not the rate determining step in contrast to other reported photocatalysts including TiO2 and carbon nitride. Collectively, structural characterisation, spectroscopic, and reactivity data are correlated with the greater surface area of nan-BiVO4 compared to bulk BiVO4. Furthermore, conversion is shown to be limited as reaction progresses. Control experiments indicate that photo-oxidation is retarded by product aldehyde and that trace amounts (<1%) of the corresponding benzoic acid, from over-oxidation, result in significant reduction in conversion.

AB - Monoclinic bismuth vanadate nanoparticles (nan-BiVO4) have been used for the selective photo-oxidation of benzyl alcohols (13 examples) to benzaldehydes under visible light irradiation using dioxygen as oxidant. Illumination with a blue LED (λmax = 470 nm) gave yields more than 30 times greater than bulk BiVO4 with >99% selectivity for several cases. Photo-oxidation of PhCH2OH/PhCD2OH isotopomers gave a kinetic isotope effect of 1.3 indicating that C–H bond activation is not the rate determining step in contrast to other reported photocatalysts including TiO2 and carbon nitride. Collectively, structural characterisation, spectroscopic, and reactivity data are correlated with the greater surface area of nan-BiVO4 compared to bulk BiVO4. Furthermore, conversion is shown to be limited as reaction progresses. Control experiments indicate that photo-oxidation is retarded by product aldehyde and that trace amounts (<1%) of the corresponding benzoic acid, from over-oxidation, result in significant reduction in conversion.

KW - Catalyst poisoning

KW - Mechanism

KW - Metal oxide

KW - Oxidation

KW - Photocatalyst

KW - Product inhibition

UR - http://www.scopus.com/inward/record.url?scp=85028979319&partnerID=8YFLogxK

U2 - 10.1016/j.jcat.2017.08.023

DO - 10.1016/j.jcat.2017.08.023

M3 - Article

AN - SCOPUS:85028979319

SN - 0021-9517

VL - 354

SP - 152

EP - 159

JO - Journal of Catalysis

JF - Journal of Catalysis

ER -