Zeolites and Zeolite-like Materials

Bert Sels,Leonid Kustov

• Editore: Elsevier
• Anno: 2016
• ISBN:
  9780444635143
• Argomento: Technik & Maschinenbau
• Categoria: Chemie- & Biochemietechnik

Zeolites and Zeolite-like Materials offers a comprehensive and up-to-date review of the important areas of zeolite synthesis, characterization, and applications. Its chapters are written in an educational, easy-to-understand format for a generation of young zeolite chemists, especially those who are just starting research on the topic and need a reference that not only reflects the current state of zeolite research, but also identifies gaps and opportunities.

The book demonstrates various applications of zeolites in heterogeneous catalysis and biomass conversion and identifies the endless possibilities that exist for this class of materials, their structures, functions, and future applications. In addition, it demonstrates that zeolite-like materials should be regarded as a living body developing towards new modern applications, thereby responding to the needs of modern technology challenges, including biomass conversion, medicine, laser techniques, and nanomaterial design, etc.

The book will be of interest not only to zeolite-focused researchers, but also to a broad scientific and non-scientific audience.

• Provides a comprehensive review of the literature pertaining to zeolites and zeolite-like materials since 2000
• Covers the chemistry of novel zeolite-like materials such as Metal-Organic Frameworks (MOFs), Covalent Organic Frameworks (COFs), hierarchical zeolite materials, new mesoporous and composite zeolite-like micro/mesoporous materials
• Presents essential information of the new zeolite-like structures, with a balanced coverage of the most important areas of the zeolite research (synthesis, characterization, adsorption, catalysis, new applications of zeolites and zeolite-like materials)
• Contains chapters prepared by known specialists who are members of the International Zeolite Association

Chapter 1

Toward Greener and Designed Synthesis of Zeolite Materials

J. Liu; J. Yu Jilin University, Changchun, PR China

Abstract

With the development of synthesis chemistry, more and more attentions have been paid toward greener and rational synthesis of materials with desired structures and functions. In this chapter, the greener and designed synthetic strategies of zeolite materials have been presented. Toward the greener synthesis of zeolites, some effective synthetic routes have been explored according to the green chemical synthesis principles and the organic-template-free synthesis, solvent-free synthesis, low toxic and cheap organic-template-directed synthesis, organic SDAs reused and mother-liquor-reused synthesis, microwave-assisted synthesis and ionothermal synthesis have been discussed. Toward the designed synthesis of zeolites, some effective approaches have been proposed by the novel SDA design, charge density mismatch, heteroatom substitution, topotactic conversion, and the like.

Keywords

Zeolite materials; Green chemistry; Design; Synthesis

1 Introduction

Zeolites are crystalline nanoporous inorganic materials formed by TO₄ tetrahedra (T = Si, Al, P, etc.), which show widespread applications in many industrial processes such as catalysis, adsorption, and separation [1–3]. In the 1940s, Barrer and Milton opened up the avenue to the synthesis of zeolites. Since then, there have been considerable efforts in the synthesis of new zeolite materials. Up to Jun. 2013, 206 types of zeolite materials have been identified by the Structure Commission of the International Zeolite Association (IZA), each of which has been named with a three-letter code [4]. Table 1 presents the new framework types approved since the 16th International Zeolite Conference (IZC-16) in 2010.

Table 1

New framework types approved by the IZA Structure Commission since IZC-16

Date Approved	Framework Type	Type Material	Tetrahedral Elements	Refs.
04/03/2011	-ITV	ITQ-37	Ge, Si	[5]
	IRR	ITQ-44	Ge, Si	[6]
	UWY	IM-20	Ge, Si	[7]
15/10/2011	JST	GaGeO-CJ63	Ga, Ge	[8]
	LTJ	Linde Type J	Si, Al	[9]
	NPT	Oxonitridophosphate-2	Ba, P	[10]
	*SFV	SSZ-57	Si	[11]
07/10/2012	BOZ	Be-10	Be, As(P)	[12]
	JOZ	LSJ-10	Be, Si	[13]
	JSN	MAPO-CJ69	Co(Zn), Al, P	[14]
	JSW	MAPO-CJ62	Co(Zn), Al, P	[15]
	PCR	IPC-4	Si	[16]

Zeolites are typically synthesized in a gel under hydrothermal/solvothermal conditions with alkali metal cations or organic amines/ammonium cations as the templates or structure-directing agents (SDAs). The reactive reagents usually include tetrahedral atom (Al, Si, P, etc.) sources, the SDA, the mineralizer (OH⁻ or F⁻), the solvent, and so on. The mixture is then heated in a polytetrafluoroethylene-lined stainless-steel autoclave under autogenous pressure at temperature below 250°C for a period of time. Many synthetic factors influence the formation of zeolites, such as the source materials, solvent, SDA, gel composition, pH value, and crystallization temperature and time. So far, there is insufficient understanding of the formation mechanism of zeolite materials. Such hydrothermal/solvothermal synthesis process coupled with the unclear formation mechanism makes the synthesis of zeolites not in an environmentally friendly and rational way. Despite this, in recent decades, many research efforts have been made toward the greener and designed synthesis of zeolites. Traditionally, green chemistry is defined as the utilization of a set of principles that reduces or eliminates the use or generation of hazardous substances in the design, manufacture, and application of chemical products [17]. It emphasizes the economy of resource and energy, minimizing waste and cost, reducing chemical hazards, ensuring process safety, and the like [18]. In the aspect of zeolite synthesis, various approaches have been exploited toward greener synthesis by considering the green chemistry principles such as cost and environmental impact reduction, waste reusing, energy efficiency, process safety, and more. Consequently, some greener synthesis methods have been developed, such as organic-template-free synthesis, solvent-free synthesis, cheap or low-toxic organic-template-directed synthesis, waste reused synthesis, microwave-assisted synthesis, ionothermal synthesis, and more. Meanwhile, many attempts have been devoted to the rational synthesis of zeolites with specific framework structures and functions by novel SDA design, charge density mismatch (CDM), heteroatom substitution, and topotactic conversion [19,20]. In this chapter, we highlight some recent progress toward greener and rational synthesis of zeolite materials.

2 Green Synthesis

Currently, with increasing attention being paid to environmental and resource issues, green chemistry has been in the spotlight as a topic of research and has become one of the main objectives of by synthetic chemists. Anastas and Warner summarize 12 principles to guide the green chemical synthesis [17]. Many relevant factors should be taken into account in the process of green synthesis, including the concepts of the use and generation of safe and low or no-toxic substances, the design of energy-efficient processes, the best disposal of waste filtrate, and the like [18].

However, for zeolite synthesis, the traditional synthesis strategies more or less violate the principles of green chemistry. The hydrothermal or solvothermal synthesis method is usually conducted at high temperature and high pressure, undoubtedly increasing the hidden danger factors and causing energy consumption; the organic templates and organic solvents are usually toxic and expensive, thus increasing the synthesis costs; the discarded filtrates contain abundant inorganic/organic species that can be reused; and the resultant products need to be calcined at high temperature to remove the occluded organic templates, further causing environmental pollution. Chemists have therefore been making great efforts toward greener synthesis of zeolite materials. Herein, we will introduce the recent representative works toward greener synthesis of zeolites from the aspects of reduced cost and environmental impact, waste ...

Indice dei contenuti

• Cover image
• Title page
• Table of Contents
• Copyright
• Contributors
• Preface
• Chapter 1: Toward Greener and Designed Synthesis of Zeolite Materials
• Chapter 2: Metal-Organic Frameworks and Related Materials: Miles to Go
• Chapter 3: Computational Chemistry of Zeolite Catalysis
• Chapter 4: Basics of Solid-State NMR for Application in Zeolite Science: Material and Reaction Characterization
• Chapter 5: Methanol to Olefins: An Insight Into Reaction Pathways and Products Formation
• Chapter 6: Y Zeolites as a Major Component of FCC Catalysts: Main Challenges in the Modification Thereof
• Chapter 7: Supported Zeolite and MOF Molecular Sieve Membranes: Preparation, Characterization, Application
• Chapter 8: Further Steps of Zeolites Toward Industrial Applications: A Short-Range Outlook
• Chapter 9: Conversion of Biomass to Chemicals: The Catalytic Role of Zeolites
• Chapter 10: Cu-Zeolite Selective Catalytic Reduction Catalysts for NOx Conversion
• Index