甲烷干气重整反应中镍基催化剂上表面积碳研究(英文)

镍基催化剂上积碳是甲烷干气重整反应急需解决的关键问题。实验采用ＴＰＳＲ、ＴＰＤ、ＸＰＳ和脉冲反应等方法系统研究了镍基催化剂表面积碳的形态和特点。热力学研究表明，在５７３ Ｋ到１２７３ Ｋ的温度范围内，催化剂的表面积碳是不可避免的。ＴＰＳＲ、ＸＰＳ和ＴＰＤ研究表明，甲烷在催化剂表面裂解将形成至少三种碳物种：Ｃα、Ｃβ和Ｃγ。这三种碳物种具有不同的表面迁移能力、热稳定性和反应活性。其中，Ｃα物种在甲烷干气重整反应中是一种非常活泼和重要的中间体；Ｃγ物种则可能是表面积碳的前驱物：部分脱氢的Ｃβ物种能够与Ｈ２或ＣＯ２反应生成ＣＨ４或ＣＯ。

SURFACE CARBON DEPOSITIONS ON NICKEL CATALYST FOR CARBON DIOXIDE REFORMING WITH METHANE

Carbon deposition on nickel catalysts is a fatal problem for carbon dioxide reforming with methane. The varieties and features of surface carbon depositions on nickel catalyst were extensively investigated by TPSR, TPD, XPS and pulse reaction methods. Thermodynamics analysis indicated that the carbon deposition is inevitable within the temperature range from 573 K to 1273 K. TPSR, XPS and TPD showed that the decomposition of methane results in the formation of at least three kinds of surface carbon species on supported nickel catalyst, carbidic C|á￡?carbonaceous C|?, and carbidic clusters C|?, which showed different surface mobility, thermal stability and reactivity.