Catalytic graphitization of graphitizable carbon by chromium, manganese and molybdenum oxides

✍ Scribed by Isao Mochida; Ryosuke Ohtsubo; Kenjiro Takeshita; Harry Marsh

• Publisher: Elsevier Science
• Year: 1980
• Tongue: English
• Weight: 426 KB
• Volume: 18
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(80)90077-9

✦ Synopsis

Catalytic graphitization of a graphitizable carbon from Kureha pitch is investigated in the temperature range 1200-2800 K, using chromia and other chromium compounds. Two distinct stages of catalytic graphitization are detected at temperatures of 1500-1800 K and above 2000 K. Values of Lc(002) and 6'o(002) are 23 nm and 673.0pm at 1800 K and 80nm and 670.9pm at 2800 K. Consideration of the phase diagram of chromium-carbon system suggests that graphitization at 2800 K may proceed via a partial dissolution-precipitation process of carbon. The known catalytic graphitization of non-graphitizable carbons at 2800 K supports this mechanism. Graphitization at 1500-1800K occurs only with a graphitizable carbon, suggesting that graphitization may proceed via the elimination of structural defects in the carbon although catalytic chemical or physical transformations may also be possible. The catalytic activity of other oxides was investigated and the high activity of manganese and molybdenum oxides is noted.