Conversion of methanol on rutile TiO₂(110) and tungsten oxide clusters: 2. The role of defects and electron transfer in bifunctional oxidic photocatalysts

Abstract

The photochemical conversion of organic compounds on tailored transition metal oxide surfaces by (UV) irradiation has found wide applications ranging from the production of chemicals to the degradation of organic...

Conversion of methanol on rutile TiO2 (110) and tungsten oxide clusters: 1. population of defect-dependent thermal reaction pathways

“…By UV irradiation, methoxy species are consumed for the photochemical formation of low temperature formaldehyde. 37 This suits earlier studies by the group of Henderson which gave evidence, that only methoxy species can be photo-oxidized on TiO 2 (110), but not undissociated methanol. 13 Therefore, we suggest that methoxy intermediates are involved in this special condensation pathway under the simultaneous formation of dimethyl ether and ethane.…”

“…38 Here, we use the identical devices under the same conditions with comparable materials as this paper is the second in a series of three consecutive papers. 37,38 Therefore, in this case, the surface characterization may be directly transferred from our previously published results. Since we do not want to reproduce all details here, we will give a brief overview and refer to central aspects in the original publication 38 and the ESI † (Fig.…”

“…3 Nevertheless, in case of rutile TiO 2 , point defects such as Ti 3+ interstitials drastically influence chemical reactions, such as O 2 activation, [30][31][32] C-C coupling [33][34][35] or alcohol (photo-) conversion. [24][25][26]36,37 Therefore it is surprising, that the role of defects in oxide-oxide systems involving tungsten oxide at TiO 2 has not been addressed before. That is one aim of this work.…”

Conversion of Alcohols on Stoichiometric and Reduced Rutile TiO2 (110): Point Defects Meet Bifunctionality in Oxide (Photo-)Chemistry

“…In contrast, recent studies gave evidence, that such sites govern for example the chemisorption and dissociation of molecular oxygen on rutile TiO 2 (110) [46,49,50] or McMurry-type aldehyde coupling [41,45,51]. In this work, the versatile role of point defects in the (photo-)chemical conversion of small alcohols is added to this list [53][54][55][56].…”

“…This becomes more important as possible products of methanol conversion such as formaldehyde, ethene, or dimethyl ether enable a rich secondary chemistry based on methanol from green sources [2]. Especially reductive C-C coupling routes (forming ethene) are of great interest because they enable the implementation of green methanol as a sustainable feedstock in future production schemes to synthesize larger carbon structures by exploiting already established petrochemical processes [56].…”