A new procedure for studying the energy transfer process at gas-solid surfaces is proposed. According to this approach, the energy distribution mode of mols. at solid surface changes from 2-dimensional Maxwell to Boltzmann depending on surface coverage. At low coverage, the reaction probability can be expressed as exp[-(E0 - Ed)/kT] and at high coverage its expression is 騡exp(-E/kT)dE (limits E0 to ?/?gexp(-E/kT)dE (limits Ed to ?. Both chem. and catalytic reactions can be simulated theor. by this unique theory. The new method has proved quite satisfactory for many examples selected from the literature. A discussion and explanation are also given on the efficiency of energy transfer, the nature of catalysis, and the definition of the accommodation coefficients-

Key words: CATALYSIS, REACTION KINETICS, ADSORPTION, SURFACE CHEMISTRY, ACTIVATION ENERGY, MATRICES, ENERGY DISTRIBUTION, COLLISION PROBABILITY METHOD