Direct Synthesis of Highly Siliceous ZnO-FAU Zeolite with Enhanced Performance in Hydrocarbon Cracking Reactions
Direct Synthesis of Highly Siliceous ZnO-FAU Zeolite with Enhanced Performance in Hydrocarbon Cracking Reactions
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DOI：
10.1021/acsmaterialslett.2c00978
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发表时间：
2022-12
影响因子：
11.4
通讯作者：
Deependra Parmar;Adam J. Mallette;N. Linares;S. Saslow;T. Terlier;J. Strohm;Lee P. Barber;H. Dai;J. García‐Martínez;J. Rimer
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文献类型：
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作者：
Deependra Parmar;Adam J. Mallette;N. Linares;S. Saslow;T. Terlier;J. Strohm;Lee P. Barber;H. Dai;J. García‐Martínez;J. Rimer
Y型沸石（八面沸石，FAU）的水热稳定性和催化活性高度依赖于其组成。高硅含量通常是催化应用所需的;然而，直接合成具有高硅含量（Si/Al > 2.5）的八面沸石是不平凡的。在这里，我们提出了一种无有机合成的FAU型沸石与Si/Al = 3.4使用氧化锌作为改性剂。光谱和显微镜技术的组合证实，ZnO是均匀分布在沸石孔内的额外的框架物种，这些物种的性质不同于散装ZnO和框架锌在Zn-FAU晶体。我们证明，增加的Si/Al比导致改善的水热稳定性，而1-己烯和枯烯的催化裂化表明，ZnO-FAU表现出显着更长的寿命相比，在内部和商业沸石Y。总的来说，本研究提出了一种简便有效的方法来制备更多的硅质FAU与增强的催化性能。
The hydrothermal stability and catalytic activity of zeolite Y (faujasite, FAU) is highly dependent on its composition. High silicon content is often desirable for catalytic applications; however, direct synthesis of faujasite with high silicon content (Si/Al > 2.5) is nontrivial. Here, we present an organic-free synthesis of FAU-type zeolite with Si/Al = 3.4 using zinc oxide as a modifier. A combination of spectroscopy and microscopy techniques confirms that ZnO is well-distributed within zeolite pores as extra-framework species, and the nature of these species differs from bulk ZnO and framework zinc in Zn-FAU crystals. We demonstrate that the increased Si/Al ratio leads to improved hydrothermal stability, while catalytic cracking of 1-hexene and cumene show that ZnO-FAU exhibits a significantly longer lifetime compared to in-house and commercial zeolite Y. Collectively, this study presents a facile and efficient method to prepare more siliceous FAU with enhanced catalytic performance.