Atomic layer deposition (ALD) is a vacuum technology for the deposition of a small number of atoms on surfaces. Its use in catalysis is growing. Here, we explored the use of ALD for introducing acid and metal sites in zeolites for performing bifunctional catalysis. Plasma-enhanced ALD involving cyclic exposure of a sample to tris(2,2,6,6-tetramethyl-3,5-heptanedionato)gallium (Ga(TMHD)₃) vapor and O₂ plasma (Ga-ALD) was used for introducing acid sites. Interestingly, Ga-ALD was found to cause preferential deposition of Pt nanoparticles via incipient wetness impregnation on the edges of COK-14 crystal plates, in contrast to previously published results on Al-ALD. Benefiting from the optimum proximity between the Ga acid and Pt metal sites, it is shown here that Ga-ALD is a way to introduce sufficient acidity into all-silica zeolite COK-14 for obtaining bifunctional catalytic behavior. Hydrogenation–dehydrogenation activity in bifunctional catalysts is typically provided by trace amounts of platinum dispersed on the zeolite. Pt-ALD was applied for finely dispersing platinum on ZSM-5 zeolite. Pt-ALD involved alternating exposure to the trimethyl(methylcyclopentadienyl)platinum(IV) (MeCpPtMe₃) precursor and ozone. The Pt-ALD method proved to be an efficient way to uniformly disperse ultra-small Pt nanoparticles onto the zeolite. The bifunctional catalytic behavior of ALD-functionalized zeolites was confirmed in the hydroconversion of the n-decane model molecule.

中文翻译：

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通过原子层沉积在双功能沸石加氢异构化和加氢裂化催化剂中创建镓酸和铂金属位点

原子层沉积（ALD）是一种用于在表面沉积少量原子的真空技术。它在催化中的用途正在增长。在这里，我们探索了ALD在分子筛中引入酸和金属位点以进行双功能催化的用途。等离子体增强的ALD涉及将样品循环暴露于三（2,2,6,6-四甲基-3,5-庚二酮基）镓（Ga（TMHD）₃）蒸气和O ₂等离子体（Ga-ALD）引入酸性位点。有趣的是，发现Ga-ALD可通过与先前在Al-ALD上发表的结果相反，COK-14晶体板边缘上的初期湿润浸渍。受益于Ga酸和Pt金属位点之间的最佳接近性，此处表明Ga-ALD是一种将足够的酸度引入全硅沸石COK-14中以获得双功能催化行为的方法。双功能催化剂中的加氢-脱氢活性通常由分散在沸石上的痕量铂提供。使用Pt-ALD将铂精细分散在ZSM-5沸石上。Pt-ALD涉及交替暴露于三甲基（甲基环戊二烯基）铂（IV）（MeCpPtMe ₃）前体和臭氧。Pt-ALD方法被证明是将超小Pt纳米颗粒均匀分散到沸石上的有效方法。在正癸烷模型分子的加氢转化中证实了ALD官能化沸石的双功能催化行为。