Jogchum Oenema

PhD Candidate
Employed since: January 2016
Phone: +31 622736364
Email: j.oenema@uu.nl
Room: David de Wied 4th floor study area

Research

Research

Bi-functional zeolite based catalysts

Zeolite based metal-acid catalysts are widely used to convert fossil or renewable hydrocarbon feedstocks into high quality fuels. To ensure maximal catalytic activity, the most favorable location of the dehydrogenating/hydrogenating metal function is in close vicinity with the Brønsted acid sites of the zeolite.[1] And for more than 50 years, the optimal intimacy between metal and zeolite acid sites was simply believed to be ‘the closer the better’, that is, metal particles were placed inside zeolite micropores. [2] However, a recent study by Zečević et al. showed that the selectivity can be greatly improved when Pt nanoparticles are located outside the zeolite, on the alumina binder of industrially used zeolite-alumina extrudates. [3] The location of the Pt particles, on the zeolite or on the alumina was controlled by exploiting the difference between strong electrostatic adsorption and ion exchange synthesis techniques. HAADF-STEM imaging combined with EDX mapping was used to confirm the location of the Pt nanoparticles in the composite support.

In this project,  the strong electrostatic adsorption, ion-exchange or impregnation of metal precursors onto zeolite, Al2O3 and Al2O3/zeolite composites will be studied. More specifically, complex Pt/Al2O3/zeolite catalysts will be studied for selective Pt deposition onto the alumina or zeolite component of the support. The location of Pt nanoparticles within within Pt/Al2O3/zeolite catalysts will be systematically studied by TEM analysis combined with various bulk characterization techniques. Furthermore, the selectivity, activity and stability of prepared catalysts will be determined in hydrocracking and hydroisomerization tests.

References:
[1] P. B. Weisz, Adv. Catal. 13 (1962) 137–190.
[2] J. Zečević et al., ACS nano. 7 (2013) 3698-3705.
[3] J. Zečević et al., Nature 528 (2015) 245–248.

C.V.

C.V.

2016 – Present
PhD candidate in the Inorganic Chemistry and Catalysis group of Utrecht University
Under supervision of Prof. K.P. de Jong and Dr. J. Zečević. Research Topic: “Bi-functional zeolite based catalysts”

2015
Internship at European Synchrotron Radiation Facility, Grenoble
Report: In-situ XAFS on noble metal promoted Co/TiO2 Fischer-Tropsch catalysts

2013-2016
Master degree: ‘Nanomaterials: Chemistry & Physics’ at Utrecht University
Thesis: “Noble metal promotion for Co/TiO2 Fischer-Tropsch catalysts”, Literature study: “XAFS on hydrodesulfurisation catalysts”

2010-2013
Bachelor degree in Chemistry at Utrecht University
Thesis: “Oligomerization of 4-Fluorostyrene:  Correlation between acid site number, strength and catalytic activity of zeolites with different topology”

Publications

Eschemann, T O; Oenema, J; Jong, De K P

Effects of noble metal promotion for Co/TiO2 Fischer-Tropsch catalysts Journal Article

Catalysis Today, 261 , pp. 60-66, 2016, (cited By 21).

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