Photoactivation of methane has been investigated on metal ion-supporte
d silica gels. Methyl radicals were detected on Na, Mg, Ca, Sr, Y, Ti,
Zn, Zr, Sn, Pb and Bi/SiO2 at 77 K by electron spin resonance (ESR).
It is found that methane was dissociated to the methyl radical on Na,
Mg, Sr, Zn and Sn supported samples with lower photon energy than C-H
bond dissociation energy in methane.