化学
甲烷
催化作用
沸石
石脑油
碳氢化合物
X射线吸收光谱法
过渡金属
原子吸收光谱法
吸收光谱法
无机化学
有机化学
量子力学
物理
作者
Ina Vollmer,Samy Ould‐Chikh,Antonio Aguilar‐Tapia,Guanna Li,Evgeny A. Pidko,Jean‐Louis Hazemann,Freek Kapteijn,Jorge Gascón
摘要
Producing aromatics directly from the smallest hydrocarbon building block, methane, is attractive because it could help satisfy increasing demand for aromatics while filling the gap created by decreased production from naphtha crackers. The system that catalyzes the direct methane dehydroaromatization (MDA) best so far is Mo supported on zeolite. Mo has shown to outperform other transition metals (TMs). Here we attempt to explain the superiority of Mo by directly comparing Fe and Mo supported on HZSM-5 zeolite. To determine the most important parameters responsible for the superior performance of Mo, detailed characterization using X-ray absorption spectroscopy (XAS) techniques combined with catalytic testing and theoretical calculations are performed. The higher abundance of mono- and dimeric sites for the Mo system, their ease of carburization in methane, as well as intrinsically lower activation energy barriers of breaking the methane C-H bond over Mo explain the better catalytic performance. In addition, a pretreatment in CO is presented to more easily carburize Fe and thereby improve its catalytic performance.
科研通智能强力驱动
Strongly Powered by AbleSci AI