Multi-functionality of Ga/ZSM-5 catalysts during anaerobic and aerobic aromatisation of n-decane
Multi-functionality of Ga/ZSM-5 catalysts during anaerobic and aerobic aromatisation of n-decane
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Ga/ZSM-5催化剂在正癸烷厌氧和好氧芳构化过程中的多功能性
DOI：
10.1039/c2sc20683h
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发表时间：
2012
期刊：
影响因子：
8.4
通讯作者：
Pradhan S
中科院分区：
文献类型：
--
作者：
Pradhan S
评价了分子筛催化剂在正庚烷气相转化中的应用，探索了中长直链烃改质的新途径。在惰性载体中进气，当接触时间为4 S时，ZSM-5和Ga/ZSM-5的初始活性在300-460°C范围内始终保持较高的活性(>；95%转化率)。母体沸石产生的裂解烃和芳烃的产率几乎相同，而Ga改性的沸石主要产生BTX和其他更重的芳烃。这种产物分布的差异与沸石内部孔结构内形成的短链烷烃是环型芳构化机理的中间产物相一致，而癸烷直接转化为重(C10-C15)芳烃发生在不受限制的外部酸中心。在好氧条件下，CO的生成速率可以忽略不计，在母体或改性分子筛上几乎检测不到CO2，即使消耗了所有的O2。Ga/ZSM-5催化剂对脱氢过程中释放的氢气的选择性氧化能力，为芳构化反应的自热操作提供了前景。尽管外部位置优先被碳保持阻挡，但直到在线(在厌氧或好氧条件下)65h后，内部孔结构的阻挡变得有限，才发生快速失活。
Zeolite catalysts have been evaluated for the gas-phase conversion of decane, to study new routes for upgrading intermediate-length straight chain hydrocarbons. For a gas-feed of dilute n-decane in an inert carrier, at a contact time of 4 s, the initial activity of ZSM-5 and Ga/ZSM-5 was consistently high (>95% conversion) over the temperature range 300–460 °C. The parent zeolite produced almost equal yields of cracked hydrocarbons and aromatics, while the Ga-modified zeolite produced predominantly BTX and other heavier aromatics. This difference in product distribution is consistent with the short-chain alkanes formed within the internal pore structure of the zeolite being intermediates in a Cyclar-type aromatisation mechanism, while the direct conversion of decane to heavy (C10–C15) aromatics occurs at the unconstrained external acid sites. Under aerobic conditions, the rate of CO formation was negligible and CO2 was barely detectable over either the parent or the Ga-modified zeolite, even though all the O2 was consumed. The ability of Ga/ZSM-5 to catalyse selective oxidation, of the H2 released during the dehydrogenation steps, thus provides the prospect of the aromatisation reaction being operated autothermally. Although the external sites are preferentially blocked by carbon retention, rapid deactivation did not occur until after 65 h on line (under either anaerobic or aerobic conditions) when blocking of the internal pore structure became limiting.
铂族金属气相催化——过去、现在和未来
DOI：
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发表时间：
2001
期刊：
影响因子：
--
作者：
S. Golunski
通讯作者：
S. Golunski
DOI：
10.1016/s0166-9834(00)80908-2
发表时间：
1988-10-17
期刊：
APPLIED CATALYSIS
影响因子：
--
作者：
GNEP, NS;DOYEMET, JY;GUISNET, M
通讯作者：
GUISNET, M