Flooding Control by Electrochemically Reduced Graphene Oxide Additives in Silver Catalyst Layers for CO Electrolysis.

Electrolyte flooding in porous catalyst layers on gas diffusion electrodes (GDE) limits the stability and high-current performance of CO and CO electrolyzers. Here, we demonstrate the in situ electroreduction of graphene oxide (GO) to reduced graphene oxide (r-GO) within a silver catalyst layer on a carbon GDE. The r-GO introduces hydrophobicity regions in the catalyst layer that help mitigate electrolyte flooding during high current density CO electrolysis to CO.

Effect of Dispersing Solvents for an Ionomer on the Performance of Copper Catalyst Layers for CO Electrolysis to Multicarbon Products.

To explore the effects of solvent-ionomer interactions in catalyst inks on the structure and performance of Cu catalyst layers (CLs) for CO electrolysis, we used a "like for like" rationale to select acetone and methanol as dispersion solvents with a distinct affinity for the ionomer backbone or sulfonated ionic heads, respectively, of the perfluorinated sulfonic acid (PFSA) ionomer Aquivion. First, we characterized the morphology and wettability of Aquivion films drop-cast from acetone- and methanol-based inks on flat Cu foils and glassy carbons. On a flat surface, the ionomer films cast from the Aquivion and acetone mixture were more continuous and hydrophobic than films cast from methanol-based inks.

Urea-Functionalized Silver Catalyst toward Efficient and Robust CO Electrolysis with Relieved Reliance on Alkali Cations.

We report a new strategy to improve the reactivity and durability of a membrane electrode assembly (MEA)-type electrolyzer for CO electrolysis to CO by modifying the silver catalyst layer with urea. Our experimental and theoretical results show that mixing urea with the silver catalyst can promote electrochemical CO reduction (COR), relieve limitations of alkali cation transport from the anolyte, and mitigate salt precipitation in the gas diffusion electrode in long-term stability tests. In a 10 mM KHCO anolyte, the urea-modified Ag catalyst achieved CO selectivity 1.

Cobalt Electrochemical Recovery from Lithium Cobalt Oxides in Deep Eutectic Choline Chloride+Urea Solvents.

Electrochemical recovery of the cobalt in deep eutectic solvent shows its promise in recycling and recovery of valuable elements from the spent lithium-ion battery due to its high selectivity and minimal environmental impacts. This work unveiled the roles of the substrates, applied potentials, and operating temperatures on the performance of cobalt electrochemical recovery in a deep eutectic choline chloride+urea solvent. The solvent contains cobalt and lithium ions extracted from lithium cobalt oxides - 3an essential lithium-ion battery cathode material.

Understanding the Effects of Anion Interactions with Ag Electrodes on Electrochemical CO Reduction in Choline Halide Electrolytes.

Interactions of electrolyte ions at electrocatalyst surfaces influence the selectivity of electrochemical CO reduction (CO R) to chemical feedstocks like CO. We investigated the effects of anion type in aqueous choline halide solutions (ChCl, ChBr, and ChI) on the selectivity of CO R to CO over an Ag foil cathode. Using an H-type cell, we observed that halide-specific adsorption at the Ag surface limits CO faradaic efficiency (FE ) at potentials more positive than -1.