Přehled

Project summary:

Metal nanoparticles immobilized at zeolite supports are important class of heterogenous catalysts for hydrogenation and dehydrogenation, reforming, and water-gas shift reactions. Zeolites, porous elementosilicates, are used to encapsulate metal nanoparticles to improve their stability. [1] Currently, in-situ encapsulation and post-synthesis functionalization are two main synthesis strategies for metal incorporation in zeolites. [2] Zeolites are often prepared as 3D solids; however, some topologies have layered representatives. Direct exfoliation of zeolites into suspension of monolayers has widened the spectrum of novel zeolitic supports for functionalization, thus design of new catalysts. [3], [4] The main objective of the thesis will be: 1) preparation of zeolites, including layered precursors; 2) functionalization of prepared supports with metal clusters; 3) characterisation of prepared materials by advanced, in-situ electron microscopy techniques; 4) optimizing the synthesis procedure to achieve better stability of prepared catalysts; and 5) catalytic tests of prepared materials and investigation of metal stability under reaction conditions. We are looking for motivated students with experience in synthesis and heterogenous catalysis. The experience in transmission electron microscopy will be an advantage.

Relevant publications:

[1] E. Eom, M. Song, J.-C. Kim, D. Kwon, D.N. Rainer, K. Gołąbek, S.C. Nam, R. Ryoo, M. Mazur, C. Jo, Confining Gold Nanoparticles in Preformed Zeolites by Post-Synthetic Modification Enhances Stability and Catalytic Reactivity and Selectivity, JACS Au. 2 (2022) 2327–2338.

[2] A. Li, Y. Zhang, C.J. Heard, K. Gołąbek, X. Ju, J. Čejka, M. Mazur, Encapsulating Metal Nanoparticles into a Layered Zeolite Precursor with Surface Silanol Nests Enhances Sintering Resistance, Angew. Chemie Int. Ed. n/a (2022).

[3] W.J. Roth, T. Sasaki, K. Wolski, Y. Song, D.-M. Tang, Y. Ebina, R. Ma, J. Grzybek, K. Kałahurska, B. Gil, M. Mazur, S. Zapotoczny, J. Cejka, Liquid dispersions of zeolite monolayers with high catalytic activity prepared by soft-chemical exfoliation, Sci. Adv. 6 (2020) eaay8163.

[4] W.J. Roth, T. Sasaki, K. Wolski, Y. Ebina, D.-M. Tang, Y. Michiue, N. Sakai, R. Ma, O. Cretu, J. Kikkawa, K. Kimoto, K. Kalahurska, B. Gil, M. Mazur, S. Zapotoczny, J. Čejka, J. Grzybek, A. Kowalczyk, Exfoliated Ferrierite-Related Unilamellar Nanosheets in Solution and Their Use for Preparation of Mixed Zeolite Hierarchical Structures, J. Am. Chem. Soc. (2021).

Fig. Zeolite functionalized with metal nanoparticles (before and after in-situ heating in TEM).

Deadline for application: March 13, 2023

Research group

Heterogeneous catalysis and advanced materials: website

Research group leader

Prof. Jiří Čejka: jiri.cejka@natur.cuni.cz

Project supervisor

Dr. Michal Mazur: michal.mazur@natur.cuni.cz

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