Molecular beam mass spectrometric studies of energy transfer and chemical reactions on heated surfaces

A modulated molecular beam mass spectrometer incorporating time‐of‐flight and threshold ionization capabilities has been used to measure translational and internal energy transfer to polyatomic molecules in collisions with heated surfaces and to observe the production of free radicals and vibrationally excited molecules in catalytic chemical reactions. In chemical reactions on a heated platinum surface, we have observed OH radicals produced in the reaction of H2 and O2, N2H3 radicals in the thermal decomposition of N2H4, vibrationally excited CO2 in the oxidation of CO, and highly vibrationally excited N2 in the thermal decomposition of NH3. The results are compared with other work on these systems.