Search results
Results From The WOW.Com Content Network
Curium(III) oxide is a compound composed of curium and oxygen with the chemical formula Cm 2 O 3. It is a crystalline solid with a unit cell that contains two curium atoms and three oxygen atoms. The simplest synthesis equation involves the reaction of curium(III) metal with O 2− : 2 Cm 3+ + 3 O 2− ---> Cm 2 O 3 . [ 1 ]
Metallic curium is annealed in air or in an oxygen atmosphere: [1] Cm + O 2 → CmO 2. Curium(III) hydroxide and curium(III) oxalate are also usually used for this purpose: Cm(OH) 4 → CmO 2 + 2H 2 O Cm(C 2 O 4) 2 → CmO 2 + 2CO 2 + 2CO. Another way is the reaction of curium(III) oxide in an oxygen atmosphere at 650 °C: [2] 2Cm 2 O 3 + O 2 ...
Curium readily reacts with oxygen forming mostly Cm 2 O 3 and CmO 2 oxides, [1] but the divalent oxide CmO is also known. [2] Black CmO 2 can be obtained by burning curium oxalate (Cm 2 (C 2 O 4) 3), nitrate (Cm(NO 3) 3), or hydroxide in pure oxygen. [3] [4] Upon heating to 600–650 °C in vacuum (about 0.01 Pa), it transforms into the whitish ...
Thermochemically, the cerium(IV) oxide–cerium(III) oxide cycle or CeO 2 /Ce 2 O 3 cycle is a two-step water splitting process that has been used for hydrogen production. [30] Because it leverages the oxygen vacancies between systems, this allows ceria in water to form hydroxyl (OH) groups. [ 31 ]
Curium readily reacts with oxygen forming mostly Cm 2 O 3 and CmO 2 oxides, [53] but the divalent oxide CmO is also known. [67] Black CmO 2 can be obtained by burning curium oxalate (Cm 2 (C 2 O 4) 3), nitrate (Cm(NO 3) 3), or hydroxide in pure oxygen. [29] [68] Upon heating to 600–650 °C in vacuum (about 0.01 Pa), it transforms into the ...
The limiting oxygen concentration (LOC), [1] also known as the minimum oxygen concentration (MOC), [2] is defined as the limiting concentration of oxygen below which combustion is not possible, independent of the concentration of fuel. It is expressed in units of volume percent of oxygen. The LOC varies with pressure and temperature.
Since the temperatures needed to achieve the reduction of the material are considerably high, the reduction of the cerium oxide can be enhanced by providing methane to the reaction. This reduces significantly the temperatures required to achieve the reduction of ceria, ranging between 800-1,000 °C, while also producing syngas in the reduction ...
Rather than combustion, organisms rely on elaborate sequences of electron-transfer reactions, often coupled to proton transfer. The direct reaction of O 2 with fuel is precluded by the oxygen reduction reaction, which produces water and adenosine triphosphate. Cytochrome c oxidase affects the oxygen reduction reaction by binding O 2 in a heme ...