Under supercritical conditions, the effects of the microporous zeolite-coated macroporous supports (i.e., ceramic-supported ZSM-5 catalysts and metal-supported ZSM-5 catalysts) on the endothermic pyrolysis process of methylcyclohexane (MCH, CHCH) were examined. The micro-macroporous composite materials were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and NH temperature-programmed desorption (NH-TPD) analysis. ZSM-5-coated AlO hollow fiber and ZSM-5-coated NiCrFeAl metal foam were both tested using an isothermal constant-pressure continuous-flow heterogeneous catalytic reactor at high temperature (550 °C) and pressure (50 bar) that simulate supersonic jet engines. The MCH pyrolysis conversions and post-pyrolysis products were determined by gas chromatography, while the deposited coke on the microporous zeolite catalysts was quantified using thermogravimetric (TG) analysis. ZSM-5-coated NiCrFeAl metal foam catalyst showed a slightly higher MCH pyrolysis conversion (%) than ZSM-5-coated AlO hollow fiber catalyst. On the other hand, the ZSM-5-coated AlO hollow fiber produces fewer aromatic hydrocarbons (benzene, toluene, and xylene, BTX), as well as cyclic or polycyclic hydrocarbons (naphthalene). Additionally, the coke deposition was approximately 2 times lower on the ZSM-5-coated AlO hollow fiber catalyst compared to the ZSM-5-coated NiCrFeAl metal foam. Furthermore, due to the endothermic nature of the catalytic pyrolysis of MCH under supercritical jet conditions over the studied microporous zeolite-coated macroporous supports, a temperature decrease of approximately 15–20 °C was observed.

中文翻译：

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微孔沸石包覆大孔载体对超临界条件下甲基环己烷催化热解的影响

在超临界条件下，考察了微孔沸石包覆的大孔载体（即陶瓷负载ZSM-5催化剂和金属负载ZSM-5催化剂）对甲基环己烷（MCH，CHCH）吸热热解过程的影响。采用 X 射线衍射 (XRD)、扫描电子显微镜 (SEM)、能量色散 X 射线光谱 (EDS) 和 NH 程序升温脱附 (NH-TPD) 分析对微大孔复合材料进行表征。 ZSM-5涂层Al2O中空纤维和ZSM-5涂层NiCrFeAl金属泡沫均使用模拟超音速射流的等温恒压连续流多相催化反应器在高温（550℃）和压力（50bar）下进行测试引擎。通过气相色谱法测定 MCH 热解转化率和热解后产物，同时使用热重 (TG) 分析对微孔沸石催化剂上沉积的焦炭进行定量。 ZSM-5 涂层 NiCrFeAl 金属泡沫催化剂的 MCH 热解转化率 (%) 略高于 ZSM-5 涂层 Al2O 中空纤维催化剂。另一方面，ZSM-5涂层Al2O中空纤维产生较少的芳香烃（苯、甲苯和二甲苯，BTX）以及环状或多环烃（萘）。此外，与 ZSM-5 涂层的 NiCrFeAl 金属泡沫相比，ZSM-5 涂层的 Al2O3 中空纤维催化剂上的焦炭沉积大约低 2 倍。此外，由于在超临界喷射条件下，MCH 在所研究的微孔沸石涂层大孔载体上催化热解的吸热性质，观察到温度下降约 15-20 °C。