摘要
用程序升温表面反应手段，系统地考察了甲烷在Ｐｔ催化剂上的吸附活化特征及甲烷分解后产生的表面碳物种．结果表明，ＣＨ４确能在ＳｉＯ２担载型Ｐｔ催化剂表面发生解离吸附，生成复杂的碳物种．其中Ｃα（３７９Ｋ）是以原子状态存在的碳化物型物种，它具有较高的配位不饱和度，因而具有较强的Ｃ－Ｃ成键能力；Ｃβ（５７２Ｋ）是以Ｍ－ＣＨｘ（ｘ≤３）形式存在的无定形碳物种，对不同金属Ｍ，其特征亦不相同；Ｃγ（８１３Ｋ）是以石墨型存在的非活性碳物种，高温有利于Ｃγ的生成，它是催化剂失活的重要因素．
The CH 4 activation on SiO 2 supported 5%Pt catalyst has been investigated by TPSR spectroscopy. The results indicate that three kinds of carbonaceous species with different structure and properties have been formed by CH 4 decomposition on the catalyst surface. The carbonaceous species are tentatively assigned as follows: C α (379 K), carbidic species; C β (572 K), carbonaceous CH x(x ≤3) species and C γ (813 K), graphitic carbon species. C α and C β may be the active intermediates which are responsible for the lengthening of C C chain. The distribution and the features of these different species depend on the nature of noble metals and the adsorption condition of methane.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
1997年第1期9-12,共4页
关键词
甲烷
吸附
活化
铂催化剂
TPSR
Methane, Adsorption, Activation, Platinum catalyst, Carbon species, Temperature programmed surface reaction
