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.

Pairing Oxygen Reduction and Water Oxidation for Dual-Pathway HO Production.

Hydrogen peroxide (HO) is a crucial chemical applied in various industry sectors. However, the current industrial anthraquinone process for HO synthesis is carbon-intensive. With sunlight and renewable electricity as energy inputs, photocatalysis and electrocatalysis have great potential for green HO production from oxygen (O) and water (HO).

Accelerating Charge Separation and CO Photoreduction in Aqueous Phase under Visible Light with Ru Nanoparticles Loaded on Ga-Doped NiTiO in a Batch Photoreactor.

Titanate perovskite (ATiO) semiconductors show prospects of being active photocatalysts in the conversion of CO to chemical fuels such as methanol (CHOH) in the aqueous phase. Some of the challenges in using ATiO are limited light-harvesting capability, rapid bulk charge recombination, and the low density of catalytic sites participating in CO reduction. To address these challenges, Ga-doped NiTiO (GNTO) photocatalysts in which Ga ions substitute for Ti ions in the crystal lattice to form electron trap states and oxygen vacancies have been synthesized in this work.

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.

Non-invasive current collectors for improved current-density distribution during CO electrolysis on super-hydrophobic electrodes.

Electrochemical reduction of CO presents an attractive way to store renewable energy in chemical bonds in a potentially carbon-neutral way. However, the available electrolyzers suffer from intrinsic problems, like flooding and salt accumulation, that must be overcome to industrialize the technology. To mitigate flooding and salt precipitation issues, researchers have used super-hydrophobic electrodes based on either expanded polytetrafluoroethylene (ePTFE) gas-diffusion layers (GDL's), or carbon-based GDL's with added PTFE.

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.

Integrating a Top-Gas Recycling and CO Electrolysis Process for H-Rich Gas Injection and Reduce CO Emissions from an Ironmaking Blast Furnace.

Introducing CO electrochemical conversion technology to the iron-making blast furnace not only reduces CO emissions, but also produces H as a byproduct that can be used as an auxiliary reductant to further decrease carbon consumption and emissions. With adequate H supply to the blast furnace, the injection of H is limited because of the disadvantageous thermodynamic characteristics of the H reduction reaction in the blast furnace. This paper presents thermodynamic analysis of H behaviour at different stages with the thermal requirement consideration of an iron-making blast furnace.

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.

Modulated Sn Oxidation States over a CuO-Derived Substrate for Selective Electrochemical CO Reduction.

Pursuing high catalytic selectivity is challenging but paramount for an efficient and low-cost CO electrochemical reduction (COR). In this work, we demonstrate a significant correlation between the selectivity of COR to formate and the duration of tin (Sn) electrodeposition over a cuprous oxide (CuO)-derived substrate. A Sn electrodeposition time of 120 s led to a cathode with a formate Faradaic efficiency of around 81% at -1.

Catalyst-Electrolyte Interactions in Aqueous Reline Solutions for Highly Selective Electrochemical CO Reduction.

Invited for this month's cover is the group of Tom Rufford at the University of Queensland. The image shows how choline chloride and urea in a reline solution interact with the surface of a silver cathode to enhance the selectivity of electrochemical CO reduction to CO. The Full Paper itself is available at 10.

Catalyst-Electrolyte Interactions in Aqueous Reline Solutions for Highly Selective Electrochemical CO Reduction.

Achieving high product selectivities is one challenge that limits viability of electrochemical CO reduction (CO R) to chemical feedstocks. Here, it was demonstrated how interactions between Ag foil cathodes and reline (choline chloride + urea) led to highly selective CO R to CO with a faradaic efficiency of (96±8) % in 50 wt % aqueous reline at -0.884 V vs.

Structure Control of Nitrogen-Rich Graphene Nanosheets Using Hydrothermal Treatment and Formaldehyde Polymerization for Supercapacitors.

Nitrogen-rich graphene nanosheets (NGN) with intentionally crumpled, stacked, and cross-linked sheet structures were developed using hydrothermal and/or formaldehyde polymerization processes. It is revealed that the hydrothermal treatment produced crumpled NGN (6.0 at% N) with a high surface area of 383 m(2)·g(-1).

Nitrogen and Phosphorous Co-Doped Graphene Monolith for Supercapacitors.

The co-doping of heteroatoms has been regarded as a promising approach to improve the energy-storage performance of graphene-based materials because of the synergetic effect of the heteroatom dopants. In this work, a single precursor melamine phosphate was used for the first time to synthesise nitrogen/phosphorus co-doped graphene (N/P-G) monoliths by a facile hydrothermal method. The nitrogen contents of 4.

Low-Temperature Synthesis of Hierarchical Amorphous Basic Nickel Carbonate Particles for Water Oxidation Catalysis.

Amorphous nickel carbonate particles are catalysts for the oxygen evolution reaction (OER), which plays a critical role in the electrochemical splitting of water. The amorphous nickel carbonate particles can be prepared at a temperature as low as 60 °C by an evaporation-induced precipitation (EIP) method. The products feature hierarchical pore structures.

Synthesis and characterization of three amino-functionalized metal-organic frameworks based on the 2-aminoterephthalic ligand.

The incorporation of Lewis base sites and open metal cation sites into metal-organic frameworks (MOFs) is a potential route to improve selective CO2 adsorption from gas mixtures. In this study, three novel amino-functionalized metal-organic frameworks (MOFs): Mg-ABDC [Mg3(ABDC)3(DMF)4], Co-ABDC [Co3(ABDC)3(DMF)4] and Sr-ABDC [Sr(ABDC)(DMF)] (ABDC = 2-aminoterephthalate) were synthesized by solvothermal reactions of 2-aminoterephthalic acid (H2ABDC) with magnesium, cobalt and strontium metal centers, respectively. Single-crystal structure analysis showed that Mg-ABDC and Co-ABDC were isostructural compounds comprising two-dimensional layered structures.