The electro-oxidation of sulfide on a Pt electrode is found to exhibit both N-NDR (negative differential resistance) and HN-NDR (hidden negative differential resistance) types of oscillations,making it the first system known to be capable of supporting both types of nonlinear instabilities without changing electrolyte compositions.Six distinct oscillation windows are observed when the external current is adjusted as the control parameter.In addition,temperature also exhibits subtle influences on the observed reaction behavior,where varying the temperature from 30.0℃ results in more complicated oscillatory phenomena.