Partial oxidation of methane to formaldehyde by lithium promoted VPO catalysts Original Research Article

The effect of the addition of lithium cations to VPO phases on the catalytic activity of methane selective oxidation is reported. Two different methods of Li+ addition were used: redox intercalation and co-precipitation. The redox intercalation procedure led to the most active promoted catalyst. XRD, FTIR, XPS characterization, oxygen isotopic exchange experiments and catalytic activity measurements using double-bed configuration were carried out. It is proposed that VPO activates methane forming of the intermediates which are further selectively oxidized by the Li+ species and that the intercalation method allows the Li+ to be well dispersed in the VPO surface and not covering completely the surface of the catalyst.