Methane partial oxidation over Pt–Ru catalyst: An investigation on the mechanism

The mechanism of the partial oxidation of methane has been investigated over a bimetallic Pt–Ru catalyst. Dedicated experiments aimed to separate and quantify the relative contribution of single reactions included in the so-called “combustion and reforming” mechanism using the same catalyst. The catalyst is 0.5% Ru and 0.5% Pt (w/w) supported on mixture of alumina, ceria and zirconia (75/4.4/20.6%, w/w), washcoated on a ceramic monolith. Steam reforming, dry reforming, direct and reverse water-gas shift reactions were investigated. The temperature range investigated is 300 < T < 800 °C, while the space velocity range is 25,000 < GHSV < 100,000 h−1. Conditions at which single side reactions are expected to occur during the partial oxidation process, were approximated by tuning the reactant composition. The experimental results are also compared with thermodynamic equilibrium calculations. The CO and H2 yields of partial oxidation have been quantitatively connected with steam and dry reforming, while the persistent water-gas shift reaction always rearranges the products and intermediates.

The relative contribution of total combustion, dry and steam reforming, and water-gas shift reactions to the methane partial oxidation has been studied by carrying out each one alone on the same bimetallic Pt–Ru catalyst. The CO and H2 yield of partial oxidation has been quantitatively related with steam and dry reforming, while the persistent water-gas shift reaction always rearranges the products and intermediates.Figure optionsDownload high-quality image (59 K)Download as PowerPoint slide