the oxidative coupling of methane (ocm) over m-na-mn/sio2 catalysts (m=w, cr, nb and v) was investigated using a continuous-flow quartz reactor at 775°c, 1 atm and 100 cm3min-1 gas flow rates, and correlated with the observed structure and redox properties.the interaction effects of the metal-metal and metal-support on the methane conversion and c2+ yield were investigated using x-ray diffracti...