Maaike van Ittersum

Research: New electrodes for CO₂ conversion – nanomorphology and composition

Electrochemical CO₂ reduction is promising to overcome the intermittent nature of renewable energy sources and close the carbon cycle. Different metals have been investigated as catalyst for the electrochemical CO₂ reduction reaction and they can be divided in to three groups based on the products they make: 1) CO producing metals (such as Ag, Au and Zn); 2) COOH producing metals (such as In, Sn and Pb); and 3) H₂ producing metals (such as Fe, Ni, Pt, Pd). Cu behaves different, as it is the only metal that is capable of producing C₂₊ products.^[1,2,3] It is known that these product specificities are related to the binding strength with the different reaction intermediates.^[1] However, the performance of the catalysts is not well enough understood to tune the product formation based on rationally designed catalysts. Hence, more research is needed to fundamentally understand the performance of the electrode and relate its composition and morphology to the catalytic activity, selectivity and stability.

In order to obtain a better understanding, my project studies two types of catalysts in more detail, namely bimetallic catalysts and nanoporous metals. Bimetallic catalysts could have an optimized binding to the reaction intermediates due to both geometric and electronic effects. When bimetallic catalysts are considered, both the composition (which metals and which ratio) and the morphology (e.g. mixed phase, core-shell particle or layered phase) can affect the performance.^[2] Nanoporous metals are interesting to investigate, as they have a high surface area and more low-coordinated sites.^[3] Nanoporous metals can for example be prepared via dealloying or by use of a sacrificial template.

[1] Bagger et al., (2017), Electrochemical CO2 Reduction: A Classification Problem, ChemPhysChem, 18(22), 3266–3273
[2] He et al, (2018), Electrocatalytic Alloys for CO2 Reduction, ChemSusChem, 11, 1, 48–57
[3] Lu et al., (2016), Electrochemical CO2 reduction: Electrocatalyst, reaction mechanism, and process engineering, Nano Energy, 29, 439–456

CV:

2020 – Present
PhD Candidate in the Materials Chemistry and Catalysis group, Utrecht University
Topic: New electrodes for CO₂ conversion – nanomorphology and composition
Promotor: prof. P.E. de Jongh; Co-promotor: dr. P. Ngene

2018 –  2020
Master Nanomaterials Science (Honours), Utrecht University
Master thesis: ‘Novel interface engineered Na fast ion conductors for all-solid-state batteries’ under supervision of dr. P. Ngene and prof. P.E. de Jongh
Research internship at Johnson Matthey Technology Center, United Kingdom

2014 – 2017
Bachelor Chemistry (Honours), Utrecht University
Bachelor thesis: ‘Cation exchange on InP-based quantum dots’ under supervision of E.J. van Harten and prof. A. Meijerink