The Highly Selective, Aerobic Oxidation of Methane to Formaldehyde over Pt Supported on Carbon: Activity, Selectivity and Stability

Platinum on carbon is an effective catalyst (10 wt.% Pt) for the selective aerobic, oxidation of methane yielding formaldehyde. In the presence of liquid water, an unusually high conversion of methane of 4.2 % was achieved yielding selectively formaldehyde (98 %) with a turnover frequency of 0.50 hr(-1). The conversion increases upon increasing the water content in the feed, which is accompanied by an increase in the selectivity for the formation of formaldehyde. This is attributed to enhanced desorption of the target product, formaldehyde, upon increased wetting of the catalyst surface. Unfortunately, the catalyst support is not stable under the applied, extremely hydrothermal conditions, but improved catalysts using a more hydrothermally stable support could be a promising route forward.