Progress in the understanding of microenvironments for eCO 2 R was made by focusing at different scales. In continuum models, the transport in the diffuse and diffusion layer in the vicinity of electrodes for eCO 2 R commonly assumes diluted conditions and planar electrodes and is modeled with the generalized modified Poisson-Nernst-Planck (gmPNP) equations . Porous electrodes were also recently studied with this approach .