Generalized Methodology for Inserting Metal Heteroatoms into the Layered Zeolite Precursor RUB-36 by Interlayer Expansion

Chaoqun Bian,Zhengxin Fei,Jianping Qiu,Xiao Wang,Longfeng Zhu,Fen Zhang,Jie Zhang,Lan Yu

doi:10.3390/cryst10060530

Chaoqun Bian, Zhengxin Fei + Show 6 more

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https://doi.org/10.3390/cryst10060530

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Abstract

The incorporation of metal heteroatoms into zeolites is an effective modification strategy for enhancing their catalytic performance. Herein, for the first time we report a generalized methodology for inserting metal heteroatoms (such as Sn, Fe, Zn, and Co) into the layered zeolite precursor RUB-36 via interlayer expansion by using the corresponding metal acetylacetate salt. Through this generalized methodology, Sn-JHP-1, Fe-JHP-1, Zn-JHP-1 and Co-JHP-1 zeolites could be successfully prepared by the reaction of RUB-36 and corresponding metal acetylacetate salt at 180 °C for 24 h in the presence of HCl solution. As a typical example, Sn-JHP-1 and calcined Sn-JHP-1 (Sn-JHP-2) zeolite is well characterized by the X-ray diffraction (XRD), diffuse reflectance ultraviolet-visible (UV-Vis), inductively coupled plasma (ICP), N2 sorption, temperature-programmed-desorption of ammonia (NH3-TPD) and X-ray photoelectron spectroscopy (XPS) techniques, which confirm the expansion of adjacent interlayers and thus the incorporation of isolated Sn sites within the zeolite structure. Notably, the obtained Sn-JHP-2 zeolite sample shows enhanced catalytic performance in the conversion of glucose to levulinic acid (LA) reaction.

Highlights

Zeolites are considered as one of the most important porous catalysts in the process of industrial production due to their crystalline structures, large surface area, excellent stability and uniform pore channels [1,2,3]
Layered Sn-JHP-1 is synthesized by insertion of Sn species through interlayer expansion reaction, which creates a novel material with catalytically active sites linking the layers
The condensation product is denoted as Sn-JHP-2 zeolite

Summary

Introduction

Zeolites are considered as one of the most important porous catalysts in the process of industrial production due to their crystalline structures, large surface area, excellent stability and uniform pore channels [1,2,3]. Zeolites with metal heteroatoms are capable of fulfilling the practical requirements of catalytic application, and have attracted increasing attention in the past years [7,8,9]. Sn-ITQ-1, which demonstrated remarkable potential in various biomass conversion reactions [11]; Wang et al, reported the RhMn@S-1 catalysts that exhibit high efficacy for the C2 -oxygenates production from syngas [12]. Layered zeolites precursor, such as MWW, PREFER and RUB-39, would be a typical class of microporous zeolites after high-temperature calcination, which plays a critical role in the industrial. The interlayer expansion reaction has been reported as a new and efficient methodology for synthesis of novel zeolites by the treatment of the above zeolites precursor [16,17,18]

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