AN INVERSE CORRELATION OF THE ENHANCEMENT EFFECT OF TETRACHLOROMETHANE AS A FEEDSTREAM ADDITIVE IN THE OXIDATIVE COUPLING OF METHANE ON SILICA-SUPPORTED ALKALINE-EARTH AND ALKALI-ALKALINE EARTH CATALYSTS WITH THE POLARIZING ABILITY OF THE ALKALINE-EARTH CATIONS

Results are reported for the oxidative coupling of methane on silica-supported alkaline earths prepared from either their acetates or chlorides with and without alkali metals as dopants and in the absence or presence of carbon tetrachloride (TCM). The addition of small quantities of TCM to the methane feedstream produces increases in the conversion of methane and the selectivities to C2 hydrocarbons which correlate with the increase in cation size and thus are inversely related to the polarizing abilities of the cations.