A Chemical Traveling Wave Arising from the Electrochemical Peroxydisulfate-Oxalate Autocatalytic Reaction
Year: 2026
Type: article
Abstract: Autocatalytic reactions commonly display reaction-diffusion behavior that can give rise to spatial patterns, oscillations, and wavefronts. Herein, we present experimental demonstrations and computational analyses of a new chemical traveling wave originating from the electrochemical S 2 O 8 2– /C 2 O 4 2– autocatalytic reaction. Following a brief electrochemical initiation step, the S 2 O 8 2– /C 2 O 4 2– chemical traveling wave propagates through the solution away from the electrode surface and is imaged using a colorimetric method based on a pH change induced by CO 2 generation at the wavefront. Following mediated initiation using the Ru(NH 3 ) 6 3+/2+ redox couple, a chemical traveling wave with an initial velocity of ∼8 μm/s propagates through the solution. Finite element simulations based on a reaction-diffusion model demonstrate that the experimentally observed chemical traveling wave behavior originates from the autocatalytic reaction between S 2 O 8 2– and C 2 O 4 2– . However, the chemical traveling wave displays nonideal reaction-diffusion behavior as indicated by a decrease in wave velocity after ∼3 min and an approach to purely diffusional mass transfer within ∼10 min. Simulated concentration profiles are consistent with a declining SO 4 ·– concentration with time due to quenching by Cl – and phenol red, resulting in a gradual dissipation of the chemical traveling wave. Lastly, the colorimetric method used to analyze the chemical traveling wave may be generally useful in monitoring the concentration distribution of dissolved CO 2 in real time.
Source: ACS electrochemistry.
Institution: University of Utah
Language: English
Subfield: Computer Networks and Communications
Field: Computer Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7135238534