Abstract: A novel composition materials based on zeolitic imidazolate framework (ZIF-8) and alumina nanofibers (NafenTM) were synthesized according to a two-step template approach by a solvothermal procedure. According to HR-TEM data, the ZIF-8 content affected its nanocrystal dispersity in the ZIF-8/Nafen composite. The DRIFT spectroscopy study of the basicity of Nafen and ZIF-8/Nafen materials using CDCl3 as a probe molecule revealed that the amount of basic sites can be tailored by the ZIF-8 nanoparticle content in the composites. Basic sites in the ZIF-8 matrix were suggested to form by the Zn-OH groups and N-moieties of nonbridging linkers in ZIF-8 framework defects, whereas the bridging oxygen atom (Al-O-Al) and -OH groups of the Nafen support can act as basic sites. The increasing ZIF-8 content in the composite leads to rising the amount of these basic sites. The strength of the strongest basic sites of Nafen and ZIF-8 materials are 955 and 858 kJ/mol, respectively. Catalytic properties of ZIF-8/Nafen were investigated in two catalytic reactions. The first reaction was synthesis of propylene glycol methyl ether (1-methoxy-2-propanol, PGME) from methanol and propylene. PGME is widely used in chemical, cosmetic and pharmaceutical industry as pollution-free solvent. It was found that the reaction rate and yield of PGME rise with the increasing content of the ZIF-8 crystals in ZIF-8/Nafen composites (Fig. 1) that is correlated to the amount of basic sites in the composites. The selectivity to PGME depends on the nature and amount of active sites that can be adjusted by the ZIF-8 content in ZIF-8/Nafen. The maximum activity and selectivity to PGME (93.8%) are observed in the presence of the pure ZIF-8 material with the smallest nanocrystal size (100-150 nm). The second reaction for testing catalytic properties of composite materials were the Knoevenagel condensation of benzaldehyde (BA) with malononitrile to 2-benzylidenemalononitrile. Reaction rate was demonstrated to rise with increasing ZIF-8 content in composite (Fig. 1), whereas selectivity reaction towards benzylidenemalononitrile (BMN) decreased due to the side reaction of aldol condensation of BA

Cite: Timofeeva M.N. , Jhung S.H. , Panchenko V.N. , Isaeva V.I. , Kustov L.M. , Lukoyanov I.A.
Tuning the Catalytic Performance of Zinc Zeolitic Imidazolate Frameworks in the Synthesis of 1-Methoxy-2-propanol from Methanol and Propylene
In compilation 5th EuChemS Inorganic Chemistry Conference, Book of Abstracts. 2019. – C.331. РИНЦ

Identifiers:

Elibrary:

41320141

Citing:

DB	Citing
Elibrary	1