Guusje Delen

PhD candidate

Employed since: September 2016
telephone: +31610213294
email: g.delen@uu.nl
David de Wied 4th floor study area

The pressing need for a more sustainable society has sparked intensive efforts in search for novel materials with controlled structure, porosity and functionalities. Such porous materials may combine high catalytic activity and selectivity with a long-term stability in the conversion of both renewable (e.g. biomass) and non-renewable feedstock when producing future transportation fuels, chemicals and pharmaceutical intermediates. The rational design and optimization of the catalytic properties of these materials is one of the keys for the transition from a fossil fuels based society to a sustainable society.

Unfortunately, useful porous catalytic solids are still largely discovered through a combination of trial-and-error, serendipity and high-throughput testing, mainly because not so much is known about the molecular details of their formation and working. Such detailed knowledge, however, is needed to tailor these porous solids towards optimal functioning.

The goal of my research is to obtain new fundamental insights in the formation principles and catalytic functioning of crystalline porous materials, namely metal organic frameworks (MOFs).

Nano-sized sheets of porous materials are constructed as model systems  amenable to nano-spectroscopic research.  To achieve this, Au substrates are functionalized to form self-assembled monolayers (SAMs) able to orient the growth of MOFs being grown by liquid phase epitaxy (LPE), or layer-by-layer growth (LBL). The effect of the variation of synthesis parameters, such as temperature, precursor solution dilution, growth time, etc., are studied.[1,2]

Novel analytical tools, such as scanning probe (SP) methods together with Raman and X-ray spectroscopy,  in combination with a specially designed high-pressure/high-temperature in-situ atomic force microscopy (AFM) cell allow for realistic measurement conditions. The novel tools and models will be used to study the intricate chemistry of synthesis, self-assembly and catalysis.

The newly developed SP-based tools are ideally suited for characterizing oxygenated molecules, which can for example be found in biomass conversion processes, as well as organic and inorganic building blocks building up the MOF materials. As a consequence, biomass conversion processes can be explored to evaluate the potential of the newly developed approach combining high pressure/temperature AFM for in-situ studies.

 

[1] O. Shekhah et al., Angew. Chem. Int. Ed., 48, 5038-5041, 2009

[2] Z. Gu, et al., Micropor. Mesopor. Mater., 211, 82-87, 2015