It was found that the temperature of the ignition limit over palladium surface at 1.75 atm, measured with a bottom-up approach by temperature, of the mixtures 30% methane + 70% hydrogen + air (f=0.9, T=317oC) and 30% propane + 70% hydrogen + air (f=1, 106oC) decreases after subsequent ignitions and amounts to 270oC, for the hydrogen-methane mix and to 320 C for the hydrogen-propane mix. The ignition limit returns to the initial value after processing of the reactor with oxygen or the air, i.e. a hysteresis effect occurs. The ignition limit of the mixtures 30% (C2, C4, C5, C6) + 70%H2 + air (f=0.6, 1.1, 1.2, 1.2, correspondingly) over palladium surface amounts to 19÷35 oC at 1.75 atm; the hysteresis effect is missing. It was found that the lean (f=0.6) 30% ethane + 70% hydrogen + air mix shows the lowest temperature of the ignition limit: 240C at 1 atm. The effective activation energy of the ignition of the mixes over Pd is estimated as ~ 2.4 ± 1 kcal/mole.