513-02-0Relevant articles and documents
Synthesis of amorphous carbon materials for lithium secondary batteries
Jeong, Bo Ock,Jeong, Seong Hun,Park, Min-Sik,Kim, Seok,Jung, Yongju
, p. 7788 - 7792 (2014)
A new and effective approach to enhance electrochemical properties of amorphous carbons is presented. Phosphorus-doped amorphous carbons have been prepared by incorporating a phosphorus compound into petroleum cokes and carbonizing them at 850°C for 1 h. It was observed that reversible capacity of amorphous carbons was greatly improved by incorporating a very small amount of phosphorus (around 1%), implying that extra lithium-storage-sites were created by phosphorus doping. In addition, the phosphorus-doped amorphous carbons showed outstanding rate capability (205 mA h/g at 5 C) and excellent capacity retention of about 90% after 50 cycles, comparable to that of undoped carbons. Very interestingly, a trade-off relation between capacity and cycle property, which is very common in electrode materials, was not found in the phosphorus-doped amorphous carbons.
Aerobic Oxidation of Phosphite Esters to Phosphate Esters by Using an Ionic-Liquid-Supported Organotelluride Reusable Catalyst
Mihoya, Aya,Shibuya, Yuga,Ito, Akane,Toyoda, Anna,Oba, Makoto,Koguchi, Shinichi
supporting information, p. 2043 - 2045 (2020/11/10)
We describe the synthesis of an ionic-liquid (IL)-supported organotelluride catalyst and its application as a recyclable catalyst for the aerobic oxidation of phosphite esters to phosphate esters. This method shows high conversion rates, allows the ready isolation and purification of the resulting products, and exhibits good reusability of the catalyst.
Cross-linked poly(4-vinylpyridine-N-oxide) as a polymer-supported oxygen atom transfer reagent
Bauer, Anna M.,Ramey, Erin E.,Oberle, Kjersti G.,Fata, Gretchen A.,Hutchison, Chloe D.,Turlington, Christopher R.
supporting information, (2019/10/02)
Oxygen atom transfer (OAT) reagents are common in biological and industrial oxidation reactions. While many heterogeneous catalysts have been utilized in OAT reactions, heterogeneous OAT reagents have not been explored. Here, cross-linked poly(4-vinylpyridine-N-oxide), called x-PVP-N-oxide, was tested as a heterogeneous OAT reagent and its oxidation chemistry compared to its molecular counterpart, pyridine-N-oxide. The insoluble oxidant x-PVP-N-oxide demonstrated comparable reactivity to pyridine-N-oxide in direct oxidation reactions of phosphines and phosphites in acetonitrile, but x-PVP-N-oxide did not react in other solvents. The polymer backbone of x-PVP-N-oxide, however, allowed for easy filtering and recycling in sequential oxidation reactions. In addition, x-PVP-N-oxide was tested as the stoichiometric oxidant in a copper-catalyzed OAT reaction to α-diazo-benzeneacetic acid methyl ester. The heterogeneous oxidant was much less reactive than pyridine-N-oxide, indicating that interaction with the metal catalyst was challenging. These results demonstrated a proof-of-concept that recyclable, polymer-supported OAT reagents could be a viable OAT reagents in direct oxidation reactions without metal catalysts.