Cerium-catalyzed Belousov-Zhabotinsky reaction

S.-H. Yau, Mechanistic studies on the cerium-catalyzed Belousov-Zhabotinsky reaction, thesis, University of Marburg, 2001. 

Cavasino, F.P. Sbriziolo, C. Turco Liveri, M.L. Effects of polymers on the Cerium (IV)-catalyzed Belousov-Zhabotinsky reaction. Communication at the NIMC-EAPS International Conference, Moscow (Russia), 1999. Conference Proceedings (Yamaguchi, T., Ed.) p.lO. The abstract focusses on the effect of poly(propylene glycol) (PPG). Experimental details on PEG were given in the full lecture. 

Example 14.3. The Belousov-Zhabotinsky reaction [22,27-29], The reaction is an oxidation of malonic acid by bromate ion in sulfuric acid, catalyzed by a Ce(III)/Ce(IV) redox couple. Many variations with other organic acids and transition-metal ions are possible [22] (Belousov used citric acid, and manganese, ruthenium, or iron can replace cerium). The color of the solution alternates between clear [Ce(III)] and pale yellow [Ce(IV)], and more dramatically between red and blue if ferroin is added as indicator. 

This subject has been reviewed by Noyes and Field,8 who give reference to the original formulation as well as a more explicit treatment. The presentation here will be given not in general terms but by means of one striking example, the oxidation of malonic acid by bromate ions catalyzed by cerium(IV). It is called the Belousov-Zhabotinsky (or BZ) reaction, after its discoverers.9 The stoichiometry of the reaction with excess malonic acid is... 

Despite the importance of the chlorite-iodide systems in the development of nonlinear chemical dynamics in the 1980s, the Belousov-Zhabotinsky(BZ) reaction remains as the most intensively studied nonlinear chemical system, and one displaying a surprising variety of behavior. Oscillations here were discovered by Belousov (1951) but largely unnoticed until the works of Zhabotinsky (1964). Extensive description of the reaction and its behavior can be found in Tyson (1985), Murray (1993), Scott (1991), or Epstein and Pojman (1998). There are several versions of the reaction, but the most common involves the oxidation of malonic acid by bromate ions BrOj in acid medium and catalyzed by cerium, which during the reaction oscillates between the Ce3+ and the Ce4+ state. Another possibility is to use as catalyst iron (Fe2+ and Fe3+). The essentials of the mechanisms were elucidated by Field et al. (1972), and lead to the three-species model known as the Oregonator (Field and Noyes, 1974). In this... 

As an example, let us examine the well-known Belousov-Zhabotinsky (BZ) reaction [15,16] of bromate with malonic acid catalyzed by cerium ions in acidic solution. 

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