Sentences with phrase «oxygen reduction»
The problem stems from oxygen reduction in deep water, a phenomenon that some scientists are observing in oceans worldwide, and that may be related to climate change.
scientificamerican.com
«One - Step Synthesis of Cobalt And Nitrogen Co-Doped Carbon Nanotubes and Their Catalytic Activity for Oxygen Reduction Reaction.»
«Metal - Organic Framework Derived Hierarchically Porous Nitrogen - Doped Carbon Nanostructures as Novel Electrocatalyst for Oxygen Reduction Reaction.»
«The efficiency is better than platinum in terms of oxygen reduction, permitting one to sidestep the most prohibitive hurdle in fuel - cell generation — the cost of the precious metal,» he said.
While unstrained lanthanum nickelate is a catalyst on its own for oxygen evolution, the strained material is an even better catalyst, enabling oxygen reduction as well.
Their study reveals the atom - level mechanisms by which doped nanomaterials catalyze oxygen reduction reactions (ORR).
Researchers Dr. James Gerken and Dr. Shannon Stahl at CME used two metal - free catalysts, an organic nitroxyl (R2NO) molecule and inorganic nitrogen oxide (NOx) source, to promote oxygen reduction.
Both the interior and exterior surfaces of this open framework structure are composed of a Pt - rich skin structure that exhibits enhanced oxygen reduction reaction activity.
Illustration of the catalytic oxygen reduction reaction on the surface of platinum - nickel nanoframes with multilayered platinum skin structure.
Nitrogen - doped carbon nanotubes or modified graphene nanoribbons may be suitable replacements for platinum for fast oxygen reduction, the key reaction in fuel cells that transform chemical energy into electricity, according to Rice University researchers.
The optimized composition has facilitated excellent oxygen reduction reaction and the novel structure has created pore channels that dramatically enhance oxygen ion diffusion and surface oxygen exchange while maintaining excellent compatibility and stability under operating conditions.
This research takes an important step in showing how oxygen reduction could be catalyzed without metals or traditional, single catalysts.
«Electrocatalytic Oxygen Reduction by Iron Tetra - arylporphyrins Bearing Pendant Proton Relays.»
«Distant Protonated Pyridine Groups in Water - Soluble Iron Porphyrin Electrocatalysts Promote Selective Oxygen Reduction to Water.»
This is true, Zelenay noted, especially in the fuel cell cathode, where a relatively slow oxygen reduction reaction, or ORR, takes place that requires significant «loading» of platinum.
«In this paper we're tying the modeling and the microscopy results with the electrochemically determined high activity of a PGM - free oxygen reduction reaction catalyst,» Zelenay said.
• PH / ORP range — The ORP (Oxygen Reduction Potential) range is what measures the number of electrons in the water, and is the key advantage in using an alkaline water machine over regular tap water.
«The GQDs add to the system an enormous amount of edge, which permits the chemistry of oxygen reduction, one of the two needed reactions for operation in a fuel cell,» Tour said.
Tests showed their ability to catalyze oxygen reduction, an essential chemical reaction in fuel cells.
«A combination of a cobalt - oxide hybrid air catalyst for oxygen reduction and a nickel - iron hydroxide hybrid air catalyst for oxygen evolution resulted in a record high - energy efficiency for a zinc - air battery, with a high specific energy density more than twice that of lithium - ion technology.»
The Pt3Ni nanoframe catalysts achieved a more than 36-fold and 22-fold enhancement in two different measures of catalytic activity (mass and specific activities, respectively) for the oxygen reduction reaction in comparison to state - of - the - art carbon - supported Pt catalysts (Pt / C) during prolonged exposure to reaction conditions.
«This nanofiber has also brought significant improvements in the performance of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER).»
This novel material significantly enhanced catalytic activity for the oxygen reduction reaction — the splitting of an O2 molecule into two oxygen ions — that is critical to fuel cells and potentially other electrochemical applications.
Catalysts that drive the oxygen reduction reaction that lets fuel cells turn chemical energy into electricity are usually made of platinum, which stands up to the acidic nature of the cell's charge - carrying electrolyte.
Oxygen atoms are depicted in pink, and hydrogen in blue, in oxygen reduction and evolution reactions that transfer electrons between two species and convert oxygen molecules to hydroxide ions and vice versa.
«We found a catalyst that is very good at driving both the opposing oxygen evolution reaction and the oxygen reduction reaction,» said senior author Ho Nyung Lee of ORNL's Materials Science and Technology Division.
In particular, an oxygen reduction catalyst extracts electrons from oxygen molecules, while an oxygen evolution catalyst drives the reaction in the opposite direction.
«Because of this new structure they're taking on, they're naturally shortening the distances between platinum atoms, which makes the platinum more active for the oxygen reduction reaction,» says Luke Roling, a graduate student in Mavrikakis» lab.
These catalysts are not selective for the methanol oxidation reaction (MOR) at the anode or the oxygen reduction reaction (ORR) at the cathode.
The material showed an oxygen reduction reaction of about 15 millivolts more in positive onset potential — the start of the reaction — and 70 percent larger current density than platinum - based catalysts.
This newly established lab is capable to design and fabricate a wide variety of advanced materials for oxygen reduction, hydrogen oxidation, water oxidation, and hydrogen evolution, among others.
By combining two simple, inexpensive, metal - free catalysts, they sped the cell's slower reaction, taking protons and electrons derived from the hydrogen fuel and combining them with oxygen to pump out water, a reaction known as the oxygen reduction reaction.
Topics include water electrolysis, fuel cell electrocatalysis (oxygen reduction, fuel oxidation, CO-tolerant materials), regenerative fuel cells, semiconductors for solar fuel production by photoelectrochemistry, and catalysts for hydrogen production and CO2 / CO conversion to fuels and chemicals.