Synthesis of Cs-W-V-O hexagonal tungsten bronzes for the partial oxidation of ethanol to acetaldehyde

Abstract

While bioethanol has been acknowledged as a relevant bioderived feedstock, acetaldehyde is an important commodity used to produce a variety of industrial chemicals, and its manufacture currently relies almost exclusively on fossil ethylene. This paper shows the effect of Cs-content in W-V-O hexagonal tungsten bronze catalysts on changes in both the physicochemical characteristics of catalysts and their catalytic performance in the aerobic transformation of ethanol to acetaldehyde, providing a promising pathway to broaden the domain of biorefinery products. The catalytic results were explained on the basis of the elimination of acid sites (responsible to the formation of ethylene and diethyl ether) by the incorporation of Cs⁺, as interstitial cations, in V-containing hexagonal tungsten bronzes. The catalysts were characterized by XRD, IR, XPS and FESEM, among others, and the incorporation of Cs⁺ into the bronze backbone, successfully demonstrated by HAXPES and confocal Raman techniques, led to 33 % EtOH conversion and 97 % acetaldehyde selectivity in the best catalyst’s formulation.