54 articles
Anion exchange membrane electrolysis
Anion exchange membrane (AEM) electrolysis is a low-temperature water electrolysis technology that splits water into hydrogen using a hydroxide-conducting polymer membrane, allowing inexpensive non-precious-metal catalysts.
Aquivion
Aquivion is a short-side-chain perfluorosulfonic acid ionomer produced by Solvay Specialty Polymers and, after 2023, Syensqo, used in fuel cells, water electrolyzers, and flow batteries.
Artificial leaf
An artificial leaf is a wireless, self-contained device using sunlight to split water into hydrogen and oxygen, imitating a natural leaf's photosynthesis to produce fuel.
Biohydrogen
Biohydrogen is hydrogen gas produced by living organisms or their enzymes rather than by industrial chemical processes, using pathways like biophotolysis, fermentation, and microbial electrolysis that can run on waste biomass.
Biophotolysis
Biophotolysis is the production of hydrogen gas by splitting water with sunlight using photoautotrophic microorganisms such as green microalgae and cyanobacteria, in direct and indirect variants.
Carbon paper
Carbon paper, in electrochemical engineering, is a porous sheet of bonded carbon fibers serving as the gas diffusion layer in fuel cells, water electrolyzers, and related devices.
CoP hydrogen-evolution catalysts
CoP hydrogen-evolution catalysts are cobalt phosphide electrocatalysts, including CoP, Co₂P, and CoP₂, that drive the hydrogen evolution reaction during water electrolysis as low-cost alternatives to platinum-group catalysts.
Copper–chlorine cycle
The copper–chlorine cycle is a hybrid thermochemical cycle for splitting water into hydrogen, using heat with one electrochemical step and a maximum temperature of about 550 °C.
Decoupled water electrolysis
Decoupled water electrolysis is a water-splitting approach in which a redox mediator separates hydrogen and oxygen production in time or space, improving safety with intermittent renewable power.
Decoupled water splitting via redox mediators
Decoupled water splitting via redox mediators is an electrolysis strategy, proposed in 2013, in which a redox mediator lets hydrogen and oxygen form in separate steps, improving safety.
Dye-sensitized photoelectrochemical cells
Dye-sensitized photoelectrochemical cells (DSPECs) use a molecular dye on a semiconductor electrode to absorb visible light and drive water splitting, producing hydrogen fuel, and can also convert CO2.
Hematite photoanodes
Hematite photoanodes are photoelectrodes made of hematite (α-Fe₂O₃), a stable, low-cost, n-type iron oxide semiconductor that absorbs sunlight and oxidizes water in photoelectrochemical water-splitting cells.
High-temperature co-electrolysis of steam and CO2
High-temperature co-electrolysis of steam and CO2 is a process in which a solid oxide electrolyzer cell at 650–900 °C turns renewable electricity, water, and CO2 into synthesis gas.
High-temperature steam electrolysis
High-temperature steam electrolysis (HTSE) splits steam into hydrogen and oxygen using solid oxide electrolysis cells at 500–1000 °C, needing roughly 35% less electricity than conventional low-temperature electrolysis.
Hydrogen crossover
Hydrogen crossover is the undesired transport of hydrogen through the polymer membrane of a PEM water electrolyzer into the oxygen-producing anode, lowering Faradaic efficiency and creating flammable hydrogen-oxygen mixtures.
Hydrogen sulfide splitting
Hydrogen sulfide splitting is the decomposition of hydrogen sulfide (H₂S) into hydrogen and sulfur, pursued as a refinery waste treatment and a low-energy route to clean hydrogen.
LaNiO3 perovskite OER catalyst
LaNiO3 perovskite OER catalyst refers to lanthanum nickelate, a metallic perovskite oxide studied as a low-cost, earth-abundant electrocatalyst for the oxygen evolution reaction in alkaline water splitting.
Layered double hydroxide electrocatalysts
Layered double hydroxide electrocatalysts are catalysts made from layered double hydroxides, two-dimensional anionic clays, used in water splitting, especially the oxygen evolution reaction for hydrogen production.
Metal exsolution in perovskite electrodes
Metal exsolution is the process where metal cations in a perovskite oxide electrode are reduced and emerge as socketed catalytic nanoparticles on the surface, used in solid oxide cells.
Microbial electrolysis cell
A microbial electrolysis cell (MEC) is a bioelectrochemical reactor in which bacteria oxidize organic matter, producing hydrogen from wastewater with much less electricity than conventional water electrolysis.
Ni-Mo catalyst for alkaline hydrogen evolution
A Ni-Mo catalyst, or NiMo alloy, is a nickel-molybdenum material used as the cathode electrocatalyst for hydrogen evolution in alkaline water electrolysis, reaching overpotentials as low as 10 to 15 mV.
Nickel foam
Nickel foam is an open-cell porous metal of interconnected nickel struts with 85–98% porosity, used as an electrode substrate in batteries and alkaline water electrolyzers.
Nickel-iron layered double hydroxide
Nickel-iron layered double hydroxide (NiFe-LDH) is a two-dimensional layered material of nickel hydroxide sheets containing trivalent iron, serving as one of the most active earth-abundant electrocatalysts for oxygen evolution in alkaline water electrolysis.
Nickel-molybdenum catalyst
A nickel-molybdenum (Ni-Mo) catalyst is a non-precious metal electrocatalyst, usually an alloy, used to speed the hydrogen evolution reaction in alkaline water electrolysis as a cheaper alternative to platinum-group cathodes.
Nickel–iron anodes for alkaline water electrolysis
Nickel–iron anodes are alkaline water electrolysis electrodes whose NiFe (oxy)hydroxide surface catalyzes the sluggish oxygen evolution reaction, the leading non-noble-metal alternative to scarce iridium and ruthenium.
Nickel–iron oxyhydroxide catalysts on nickel foam for alkaline electrolyzers
Nickel–iron oxyhydroxide catalysts grown directly on porous nickel foam are self-supported, precious-metal-free anode electrodes for the oxygen evolution reaction in alkaline water electrolysis, the standard non-noble benchmark.
NiFeOx oxygen evolution catalyst
NiFeOx is a low-cost nickel-iron oxide or oxyhydroxide electrocatalyst that accelerates the oxygen evolution reaction in alkaline water electrolysis, the leading earth-abundant alternative to IrO2 and RuO2 for hydrogen production.
NiMo alkaline hydrogen-evolution electrodes
NiMo alkaline hydrogen-evolution electrodes are nickel–molybdenum alloy cathodes that catalyze the hydrogen evolution reaction in alkaline electrolyte, studied as platinum-free catalysts for alkaline and anion-exchange-membrane water electrolyzers.
Oxygen vacancies as OER active sites in perovskites
Oxygen vacancies in perovskite oxides, written ABO3-δ, are missing lattice oxygens that serve as catalytic active sites for the oxygen evolution reaction in water electrolysis and metal-air batteries.
Oxygen-depolarized cathode
An oxygen-depolarized cathode (ODC) is a gas diffusion electrode in chlorine electrolysis that reduces oxygen instead of evolving hydrogen, cutting electricity demand by about 30 percent.