Pulse-MS studies on CH4/CD4 isotope effect in the partial oxidation of methane to syngas over Pt/α-Al2Ch3

Abstract

By replacing CH4 + O2 with CD4 + O2, the deuterium isotope effect in the partial oxidation of methane over Pt/α-Al2O3 was studied in the temperature range of 550-650°C using the pulse-MS method. The effect of space velocity of carrier gas and CO2 reforming of CH4 to syngas were also investigated, No deuterium isotope effect was observed for CH4 conversion whereas CO formation showed a normal deuterium isotope effect. The surface reaction between adsorbed hydrocarbon species and adsorbed oxygen species to CO formation may be a relatively slow step. The results support the parallel mechanism, namely CO and CO2 are simultaneously formed in parallel from the direct oxidation of methane.