Facet-Selective Bromide Adsorption at High-index Facets of Copper Sulfides for Improved Electrochemical Nitrogen Reduction Activity and Selectivity

Ammonia is a promising liquid-phase carrier for the storage, transport, and deployment of carbon-free energy. However, the realization of an ammonia economy is predicated on the availability of green methods for the production of ammonia powered by electricity from renewable sources or by solar energy. Here, we demonstrate the synthesis of ammonium from nitrate powered by a synergistic combination of electricity and light. We use an electrocatalyst composed of gold nanoparticles, which have dual attributes of electrochemical nitrate reduction activity and visible-light-harvesting ability due to their localized surface plasmon resonances. Plasmonic excitation of the electrocatalyst induces ammonium synthesis with up to a 15× boost in activity relative to conventional electrocatalysis. We devise a strategy to account for the effect of photothermal heating of the electrode surface, which allows the observed enhancement to be attributed to non-thermal effects such as energetic carriers and charged interfaces induced by plasmonic excitation. The synergy between electrochemical activation and plasmonic activation is the most optimal at a potential close to the onset of nitrate reduction. Plasmon-assisted electrochemistry presents an opportunity for conventional limits of electrocatalytic conversion to be surpassed due to non-equilibrium conditions generated by plasmonic excitation.

Oxygen electrochemical reduction on gold–polyaniline (Au–PANI) porous nanocomposite-modified glassy carbon electrode in basic media was described. The as-prepared Au–PANI porous nanocomposite showed superior tunable activity for electrochemical reduction of oxygen. The specific surface area of Au–PANI porous nanocomposites was evaluated to be about 11.3 m2 g−1 through a convenient voltammetric approach. Rotating ring-disk electrode experiments further demonstrated the number of electrons exchanged in oxygen reduction increased from 2e to 4e with increasing the trigger potential from 300, to 500, 700 mV. The tunable activity in electrochemical reduction of oxygen was achieved as a result of positive potential-induced formation and reduction of Au surface oxide. However, the tunable oxygen reduction reaction is fit for applying potential in a linear positive-going potential sweep. Irreversible ORR tunability was found after a more active surface formed at 700 mV. To optimize the applied potential window on these Au-based porous materials has potential applications such as in electrochemical sensing, fuel cells, or getting rid of the interference from the coexisted substances.

Polyvinyl alcohol-modified gold nanoparticles with record-high activity for electrochemical reduction of CO2 to CO

True or False in Electrochemical Nitrogen Reduction

Ligand-free gold nanoparticles supported on mesoporous carbon as electrocatalysts for CO2 reduction

Galvanic displacement in an ionic liquid was utilized to deposit palladium (Pd) or platinum (Pt) onto a copper (Cu) surface. Compared to water and conventional organic solvents, the relatively high viscosity of ionic liquids offers a distinct advantage in controlling the modification process, as the reduced mass transfer leads to a slower and more manageable displacement rate. This control is crucial; excessive deposition of Pd or Pt on the Cu surface can result in diminished, rather than enhanced, electrochemical nitrate reduction activity. Cu surfaces modified with an appropriate amount of Pd or Pt exhibited improved electrochemical performance toward both nitrate (NO3−) and nitrite (NO2−) reduction. This enhancement is likely attributed to the increased porosity induced during the galvanic displacement process, as well as synergistic effects between Pd/Pt and Cu. Overall, galvanic displacement in ionic liquids represents a practical and effective strategy for the synthesis of Cu‐based electrocatalysts for electrochemical nitrate reduction.

Enhancement of Electrochemical Nitrogen Reduction Activity and Suppression of Hydrogen Evolution Reaction for Transition Metal Oxide Catalysts: The Role of Proton Intercalation and Heteroatom Doping

Spin-Enhanced C–C Coupling in CO ₂ Electroreduction with Oxide-Derived Copper

Medium-entropy perovskite Pr0.4Ba0.2Ca0.2La0.2Co0.2Fe0.8O3 as a promising bifunctional electrocatalyst for electrochemical energy conversion device

Au–Pd core–shell nanoparticles can convert CO2 into CO with a high selectivity and mass activity due to the more balanced *COOH/*CO adsorption.

Facile synthesis of core-shell Co-MOF with hierarchical porosity for enhanced electrochemical detection of furaltadone in aquaculture water

Electrochemical reactors operating at intermediate temperatures (200 – 400 °C) can potentially have several advantages over their high temperature (600- 1000 °C) and low temperature (< 100 °C) counterparts. For example their potential of an increased catalytic activity enabling a decrease in material cost compared to low temperature cells, and can be thermally integrated into other chemical processes like synthesis of synthetic fuels and chemicals, such as methanol and ammonia.Electrochemical reduction of CO2 to chemical building blocks such as CO, CH3OH, and CH4 is a dream for electrochemists, and high faradaic efficiencies have been reported for liquid electrochemical cells operated at ambient temperature, using e.g. Cu electrodes [1]. However, selectivity and electrochemical activity are far from being technically relevant, so that heterogeneous catalysis processes still are the matter of choice. Even more difficult is the electrochemical reduction of nitrogen f.i. to ammonia.In this contribution, activities at DTU Energy are summarized using solid state electrochemical cells under operating conditions close to the well-known catalytic synthesis of methanol and ammonia. For CO2 reduction, cells based on CsH2PO4 as electrolyte and Cu based cathodes have been investigated towards their electrochemical activity in both H2/H2O and H2/H2O/CO2 containing atmospheres at elevated temperatures of 240 °C. Proton conducting ceramics cells based on barium cerate with Mo and Fe electrodes have been characterized in H2/N2 atmospheres between 300 and 500 °C. Electrochemical impedance analysis point towards a predominant hydrogen evolution and the role of adsorption and desorption processes as well as overpotential will be discussed.[1] Y. Hori, Modern Aspects of Electrochemistry: Electrochemical CO2 Reduction on Metal Electrodes, Springer New York, USA 42 (2008), 89-189.

The Cu(II)/Cu(I) redox properties and electrochemical O2 reduction activity of a series of Cu(II)-complexes with pyridylalkylamine ligands were investigated in a neutral buffer solution. The relationship between Cu(II)/Cu(I) redox properties and O2 reduction activity was clearly demonstrated by voltammetric analyses.

Improving electrochemical nitrate reduction activity of layered perovskite oxide La2CuO4 via B-site doping

Lead-modified graphite felt electrode with improved [formula omitted] electrochemical activity for vanadium redox flow battery