A study of the partial oxidation of methane to methanol and formaldehyde, over various silica supported catalysts, has been undertaken at elevated pressures (up to 1520 kPa) between 500 degrees C and 600 degrees C. C-2 products were observed with O-2 as oxidant; but not with N2O. O-2 was much more reactive than N2O in all conditions examined, but no catalytic effect could be observed with O-2. Formaldehyde was generally the major partial oxygenated product observed. (C) 1998 Elsevier Science B.V. All rights reserved.