Poly-Amide Modified Copper Foam Electrodes for Enhanced Electrochemical Reduction of Carbon Dioxide

Abstract

A strategy to modulate the electrocatalytic activity of copper towards CO 2 reduction involving adsorption of acrylamide, acrylic acid and allylamine polymers is presented. Modification of electrodeposited copper foam with poly(acrylamide) leads to a significant enhancement in faradaic efficiency for ethylene from 13% (unmodified foam) to 26% at-0.96 V vs. RHE, whereas methane yield is unaffected. Effects from crystalline phase distribution and copper oxide phases are ruled out as the source of enhancement through XPS and in-situ XRD analysis. DFT calculations reveal that poly(acrylamide) adsorbs on the copper surface via the oxygen atom on the carbonyl groups, and enhances ethylene formation by i) charge donation to the copper surface that activates 1

Sustainable Membrane‐Coated Electrodes for CO2 Electroreduction to Methanol in Alkaline Media

“…The values obtained for d were 196 cm, 264 cm, 241 cm and 230 cm, for the CS : PVA, Cu/CS : PVA, Cu-UZAR-S3/ CS : PVA and Cu-Y/CS : PVA MCE, respectively. These values are higher than those reported in literature, [58,59] though, confirming the additional resistance opposed by the membrane over-layer and expecting the existence of non-idealities when this membrane over-layer is a mixed matrix membrane (MMM), [61,62] but yet the diffusion layer values correlated with the SEM observations taken of the surface morphologies of the electrodes after the electroreduction experiments, discussed below regarding Figure 4.…”

“…This could be related to the differences in water uptake, water permeability and anion conductivity among the Cu-UZAR-S3/CS : PVA, Cu-Y/ CS : PVA and Cu/CS : PVA MMM over-layers observed previously. [58] Conductive polypyrrole could also increase the stability of Cu 2 O NPs in the CO 2 RR to methanol. [48] Therefore, this Cu/CS : PVA membrane layer generated the highest current densities generated of all MCE in Table 2, but the catalyst in metallic form seemed to be less accessible for CO 2 and its ionic forms, so the methanol production dropped, in favor of HER as dominant reaction.…”

“…[58] The encapsulation of a nanoparticulate metal catalyst in a membrane over-layer with OH À functional groups that interact with the catalyst active sites and CO 2derived reagents can avoid the dissolution of metal NPs and facilitate the membrane fabrication in a mixed matrix containing ions. [58] The encapsulation of a nanoparticulate metal catalyst in a membrane over-layer with OH À functional groups that interact with the catalyst active sites and CO 2derived reagents can avoid the dissolution of metal NPs and facilitate the membrane fabrication in a mixed matrix containing ions.…”

“…Ahn et al reported that the coating of Cu foam electrode surfaces could both activate and stabilize the electrode surface towards different reaction intermediates. [58] Conductive polypyrrole could also increase the stability of Cu 2 O NPs in the CO 2 RR to methanol. [47] The diffusion layer thickness can be estimated using the Nernst diffusion layer Equation (2),…”

“…Because the CS : PVA MCE showed a better performance than the uncoated GDE prepared in this work, this was first attributed to the protection provided by the membrane overlayer and the CS binding properties in the catalytic layer mentioned earlier. [58] The encapsulation of a nanoparticulate metal catalyst in a membrane over-layer with OH À functional groups that interact with the catalyst active sites and CO 2derived reagents can avoid the dissolution of metal NPs and facilitate the membrane fabrication in a mixed matrix containing ions. [38] The membrane over-layer of the Cu/CS : PVA MCE (Figure 4c) was thinner than that of the CS : PVA MCE (Figure 4b) after the electrolysis experiments.…”