PULSE-MS STUDIES ON CH4 CD4 ISOTOPE EFFECT IN THE PARTIAL OXIDATION OF METHANE TO SYNGAS OVER PT/ALPHA-AL2O3/

By replacing CH4 + O-2 with CD4 + O-2, the deuterium isotope effect in the partial oxidation of methane over Pt/-alphaAl2O3 was studied in t he temperature range of 550-650 degrees C using the pulse-MS method. T he effect of space velocity of carrier gas and CO2 reforming of CH4 to syngas were also investigated. No deuterium isotope effect was observ ed for CH4 conversion whereas CO formation showed a normal deuterium i sotope effect. The surface reaction between adsorbed hydrocarbon speci es and adsorbed oxygen species to CO formation may be a relatively slo w step. The results support the parallel mechanism, namely CO and CO2 are simultaneously formed in parallel from the direct oxidation of met hane.