Electrochemical modification of the catalytic properties of composite membranes of substituted Bi4V2O11 (BIMEVOX) for propane oxidation in a catalytic dense membrane reactor

Dense BICOVOX membrane, bulk BICOVOX/Au cermet membrane and BICOVOX membrane with a BICOVOX/Au cermet on its surfaces are investigated in the partial oxidation of propane under open circuit voltage (OCV) and under electrical bias at 700 °C. The propane conversion remains in the range 10–12% whatever the conditions of polarisation. Mostly cracking products are observed. Hydrogen is the main product with a selectivity around 55–60%. At OCV, no product of oxidation is detected except water which can not be quantified. On the membrane with BICOVOX/Au cermet electrodes on surface, traces of CO are observed as well as a small increase of propylene content under anodic polarisation. This can be explained by partial oxidation and oxidative dehydrogenation of propane, respectively. An anodic polarisation leads to a decrease of hydrogen due to its oxidation into water. In contrast, an increase of the hydrogen content is observed under cathodic polarisation. The effects on the membrane are modest, but they show the possibility that such a system offers for modifying the catalytic properties of membrane materials in a CDMR.