Hydrogen and deuterium combustion over Rh, Ru, Pd and Pt wires at total pressures up to 200 Torr and initial temperatures up to 500 degrees C is investigated in order to establish the temperature dependencies of autoignition limits over noble metal surfaces and to indicate the governing factors of gas ignition by a catalytic surface. It was found that Rh, Ru and Pd surfaces treated with 2H(2) + O-2 ignitions manifest the defects in the form of openings, which are located on surface defects. It was shown that before ignition, the catalytic wire is not heated up uniformly; and initial centers of the ignition occur. It was shown that Rh is the most effective catalyst of 2H(2) + O-2 ignition, the lowest ignition temperature over Rh coated Pd wire (Rh/Pd) was 210 degrees C, for Ru/Pd and Pd -300 degrees C, for Pt wire -410 degrees C at total pressures less than 200 Torr. A hysteresis phenomenon was observed over Ru/Pd, Pt and Pd wires; namely the ignition limit value measured over the wire when increasing temperature from a state of no ignition, is higher than the value measured when decreasing temperature from a state of autoignition. It was shown that Rh is the most effective catalyst of 2D(2) + O-2 ignition, in this case the lowest ignition temperature over Rh coated Pd wire (Rh/Pd) was 100 degrees C. It is more accurate to speak about ignition over noble metals hydrides/deuterides; thus, the lowest ignition limit of 2D(2) + O-2 over rhodium deuteride was 100 degrees C; thus, D-2 is more flammable than H-2 over Rh and Pd. The results obtained indicate the existence of a kinetic inverse isotope effect, which affects the reactivity of MeH and MeD, where Me =Rh, Pd. (C) 2020 The Combustion Institute. Published by Elsevier Inc. All rights reserved.