Lithium peroxide, decomposition

Because of the delay in decomposition of the peroxide, oxygen evolution follows carbon dioxide sorption. A catalyst is required to obtain total decomposition of the peroxides 2 wt % nickel sulfate often is used. The temperature of the bed is the controlling variable 204°C is required to produce the best decomposition rates (18). The reaction mechanism for sodium peroxide is the same as for lithium peroxide, ie, both carbon dioxide and moisture are required to generate oxygen. Sodium peroxide has been used extensively in breathing apparatus. 

Two studies [24,25] identify the rate-limiting step in the decomposition of lithium peroxide (LijOj), 540 to 600 K, as bond rupture in the O2 ion, for which the measured value of , is 220 kJ mol". The energy requirement for reaction is partially diminished by the decrease in the interionic distance (Li to O ) in the product (LijO). This conclusion was supported by a later isotopic study [26]. Zero-order kinetic behaviour was reported [25] for LijOj decomposition and it was suggested [24] that solid-solution formation (LijOj/LijO) occurred when or was less than 0.5. LijO sublimes below its melting point. 

Lithium (reported as lithium oxide) is determined by adding water and a trace of platinum black, boiling until peroxide decomposition is complete, and titrating with standard acid. Peroxide oxygen is determined by direct... 

The checkers report partial decomposition to lithium peroxide as a result of prolonged drying by suction. 

In a series of experiments on the thermal decomposition of lithium peroxide,... 

Beyer H, Meini S, Tsiouvaras N et al (2013) Thermal and electrochemical decomposition of lithium peroxide in non-catalyzed carbon cathodes for Li-air batteries. Phys Chem Chem Phys 15 11025-11037. doi 10.1039/c3cp51056e... 

Lithium Oxide. Lithium oxide [12057-24-8], Li20, can be prepared by heating very pure lithium hydroxide to about 800°C under vacuum or by thermal decomposition of the peroxide (67). Lithium oxide is very reactive with carbon dioxide or water. It has been considered as a potential high temperature neutron target for tritium production (68). 

The oxidation of azo compounds with hydrogen peroxide in an acetic acid medium or with peracetic acid has been carried out by many investigators. For example, in a study of the 4,4 -dialkoxyazoxybenzenes, which are of interest in the field of liquid crystals, the corresponding alkoxynitrobenzenes were reduced with lithium aluminum hydride to the corresponding azo stage and, after decomposition of the reducing agent and removal of the solvent, the product residue was taken up in acetic acid and oxidized at 65°C for 36 hr with... 

As previously indicated, lithium hydroxide begins to decompose into the monoxide 52 when heated above its m.p., but the other hydroxides are not so readily decomposed, and although some decomposition does occur at a red heat, the monoxides of the other alkali metals cannot be obtained in this way. When the hydroxides are heated in air some oxygen is absorbed, and the product then furnishes reactions indicating that some peroxide has been formed. 

Using the normal addition procedure (02 diffusion into a 75/25 benzene/THF solution of poly(styryl)lithium) the 37% dimer fraction analyzed for 19% alkyl radical dimer and 18% macroperoxide after LiAlH4 reduction. The yield of macroperoxide was also confirmed by thermal decomposition experiments in refluxing toluene, followed again by size exclusion chromatography analysis of the dimer fraction. The amount of hydroperoxide could be deduced from the difference between the amounts of total peroxide (determined by iodometric titration) versus the amount of macroperoxide determined by LiAlH4 reduction. 

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