推 rememberkog: 可能是隔絕速率會變慢 但從能量來看是更傾向吧 10/03 14:15
→ eroc116118: 意思是說隔絕造成速率變慢，同時也會造成能階降低嗎 10/04 00:43
→ eroc116118: 就看是反應速率抑制多 或能階降低迅速石墨化的影響多 10/04 00:46
→ eroc116118: 是這個意思嗎？ 10/04 00:47
推 rememberkog: 可能吧 我也沒做過 僅僅提供一個想法 10/06 15:26
眾所皆知鐵具有催化鑽石，使其更容易石墨化的能力
(第一篇論文)
多數論文有提到
若氧參與將形成氧化鐵，催化的能力會比單純只有鐵更好
鑽石更容易石墨化
(第二篇論文)
然而我最近看了一篇論文
他提到在「合成鑽石」時
若氧在鐵表面產生氧化鐵層
這種氧化鐵層會限制鐵與石墨的接觸
進而降低鑽石的生長速率(催化能力降低)
(第三篇論文)
另一篇論文也提到
透過氧-鐵複合物催化劑可以大大降低活化能
來增強鑽石-石墨之間的正向與逆向反應
抑制石墨化、合成鑽石的效果更強
(說實話這邊我就看不太懂他在說什麼)
第三篇論文段落擷取：Compared to metal, metal oxide is not an effective catalyst in synthesis of
diamond. In fact, researchers have found that iron oxide covering iron
catalyst will lower the catalytic efficiency for diamond growth by limiting
the direct contact between graphite and iron, and such restraining effect
becomes stronger with an increasing oxide thickness [10]. As catalysts
enhance both, the forward and backward reactions of diamond-graphite
transition by drastically lowering the activation energy, the formation of
metal oxide on clean metal surface shall also restrain the graphitization of
diamond. An increased oxygen pressure that accelerates the oxide growth could
strengthen such influence. Although it is theoretically possible for carbon
to extract oxygen from metal oxide, such reduction reaction usually requires
the elevated temperature, similar to the oxidation of diamond.
總之，若把這幾篇論文拿來一起思考，就讓我搞不太懂
為什麼有些論文寫氧化鐵會更易使鑽石石墨化
有些則寫氧化鐵可以隔離鐵與鑽石，鑽石會比較不易石墨化
到底誰對誰錯？有點矛盾
請求化學高手回答...苦惱很久
註：若想看那幾篇論文可以留言，我會私信給檔案，感謝
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