Excitability of the ferroin-catalyzed Belousov–Zhabotinsky reaction with pyrogallol

Depending on the concentrations of reagents, the state of the Belousov–Zhabotinsky (BZ) reaction with pyrogallol (PG) is found to be stable reduced, excitable, oscillatory, or stable oxidized. For the oscillating solutions, the period decreases when either [H2SO4] or [NaBrO3] is increased, however, it increases with [PG]. For unstirred media, the excitable and oscillatory solutions support propagating waves whose velocity increases with [H2SO4] and [NaBrO3], however it decreases when [PG] increased. Finally, we demonstrate that the well-known inhibitory effect of oxygen, which weakens the system excitability in the classical BZ reaction, disappears in the BZ reaction with PG.