Adsorption of hydrogen and methane on a preirradiated surface of γ-Al₂O₃ produces an afterglow, which has been described as a photoinduced chesorluminescence (PhICL), whose spectral features identify with the intrinsic photoluminescence of alumina. The emission spectrum consists of at least four overlapping single emission bands. For methane adsorption, the PhICL phenomenon is seen only if the solid is preirradiated in the presence of oxygen. Emission decay kinetics of the PhICL effect for γ-Al₂O₃ reveal two wavelength regimes: a short wavelength regime at λ = 300-370 nm (decay time τ = 1.1 ± 0.2 s; signal width = 2.8 s), and a longer wavelength regime at λ = 380-700 nm (decay time τ = 2.1 ± 0.1 s; signal width = 4.3 s). A model is proposed in which there exist two different emission centers and, thus, two different pathways for emission decay. In the first, emission originates with electron trapping by such deep energy traps as anion vacancies {e^- + V_a → F⁺ + hv₁} to yield electron F-type color centers, whereas in the second, emission originates from electron/trapped hole recombination {e^- + O_s^̇- → O _s^2- + hv₂}. The first common step of the pathways is homolytic dissociative chemisorption of hydrogen and methane upon interaction with surface-active hole centers O_s^̇-, produced upon preirradiation of alumina, to give atomic hydrogen H ^̇ and methyl radicals CH₃^̇. Thermoprogrammed desorption spectra of photoadsorbed or postsorbed oxygen show that adsorbed oxygen interacts with atomic hydrogen and methyl radicals. The products of thermodesorption were H₂O for hydrogen and H ₂O, CO₂, and CH₃CH₃ for methane. The Solonitsyn memory effect coefficient was also evaluated for oxygen photoadsorption.