甲烷无氧脱氢芳构化W/MCM-22基催化剂积炭的表征研究  

Characterization of Carbon Deposits on W/MCM-22-based Catalysts for Dehydro-aromatization of CH_4 in Absence of O_2

作　　者：黄利强[1] 林种玉[1] 于腊佳[1] 廖新丽[1] 曾金龙[1] 张鸿斌[1] 

机构地区：[1]厦门大学化学化工学院

出　　处：《厦门大学学报（自然科学版）》2005年第1期71-76,共6页Journal of Xiamen University：Natural Science

基　　金：国家重点基础研究规划项目"天然气;煤层气优化利用的催化基础"(G1999022400)资助

摘　　要：利用TEM和XRD对积炭的甲烷无氧脱氢芳构化W/MCM-22基催化剂及其参比样进行观测,结果显示,催化剂上的积炭主要是无定形碳,间或有为数甚少的碳纳米管或碳纤维,无可观量石墨状碳存在的XRD证据.利用氢氟酸溶液处理积炭的W/MCM-22基催化剂试样,溶解除去沸石分子筛基催化剂组分,后用溶剂CH2Cl2进行萃取分离,可得不溶性和可溶性两类碳沉积物,前者占主体量,后者占总积炭量不足10%;利用FTIR、MS和1H NMR等谱学方法对积炭进行表征,结果表明,可溶性碳沉积物主要是一些分子量在523～745范围的饱和脂肪烃高聚物,不溶性碳沉积物主要为稠环芳烃大分子.With XRD and TEM methods,the texture and structure of carbon deposits on the W/MCM-22-based catalysts for reaction of dehydro-aromatization of CH_4 in absence of O_2 (DHAM) were observed,and the results showed that those carbon deposits on the catalysts undergoing 6 h of DHAM reaction were mainly amorphous carbon,occasionally involving a small quantity of carbon nanotubes and nanofibers,and that there was no confident XRD evidence for existence of graphitized carbon.With hydrofluoric acid to immerse the used catalyst to resolve the W/MCM-22-based catalyst components,followed by extraction by CH_2Cl_2,the two types of carbon deposits,soluble and insoluble in CH_2Cl_2 solvent,were separately obtained.Using FTIR,MS,and (~1H) NMR spectroscopies,characterization of those carbon deposits were done.The results indicated that the CH_2Cl_2-soluble carbon deposits were mainly a series of polymer of saturated aliphatic hydrocarbons with molecular weight in range of 523~745,and the CH_2Cl_2-insoluble carbon deposits were mainly macromolecular compounds of condensed aromatics.

关 键 词：MCM-22 催化剂 无定形碳 表征 积炭 不溶性 甲烷 脱氢芳构化 谱学 萃取分离 

分 类 号：O643[理学—物理化学] TQ424.25[理学—化学]