DIRECT PARTIAL OXIDATION OF METHANE INTO SYNTHESIS GAS OVER RH YSZ/AG/

An electrochemical membrane reactor, Rh\YSZ\Ag, has been tested for th e partial oxidation of CH4 to CO/H-2 under 'oxygen pumping' through YS Z. An ionically transported oxygen species over the Rh anode was highl y active for the partial oxidation. The reaction mode of the CH4 oxida tion strongly depends on the surface state of Rh particles; a highly o xidized Rh surface accelerates complete oxidation of CH4 to CO2/H2O, w hile a reduced Rh surface catalyzes the partial oxidation to CO/H-2. O xygen concentration over the Rh predominantly determines the selectivi ty; a high oxygen concentration leads to the complete oxidation, while an adsorbed oxygen species gives the partial oxidation.