Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Diffusion of a redox active molecule

Please login with a confirmed email address before reporting spam

Hello, I am trying to model the diffusion of a redox active molecule. I tried to use the Electroanalysis physics but I am not sure how to choose my geometry and reaction. I tried choosing a quartre circle (radius 0.01m) geometry and a point located on one of the circles boundries (r direction) at 0.0015m (the electrode radius). I want to take in account that there's a redox reaction on the eletrode and to see the diffusion of the oxidized species. I chose as initial values 0 for the oxidized species, but not sure what to do about the reduced species. I want to limit it to be only in the electrode area and not in the entire domain...I used a concentraion boundry and tried different options for cRed and cOx (redcued and oxidized species), but I am getting negative concentrations in the solution: option 1: cRed = 0.2e-6 - cOx cOx = 0

option 2: cRed - 0,2e-6 cOx = 0

How do i avoid these negative concentrations?



1 Reply Last Post 2020年7月6日 GMT-4 05:39

Please login with a confirmed email address before reporting spam

Posted: 4 years ago 2020年7月6日 GMT-4 05:39

Hello Maya, Have you checked this knowledge base entry already? https://www.comsol.com/support/knowledgebase/952

Hello Maya, Have you checked this knowledge base entry already? https://www.comsol.com/support/knowledgebase/952

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.