M.T.M. Koper, Co-promotor: D.G.H. Hetterscheid

In this thesis we have discussed several parameters that affect the electrochemical conversion of enviromentaly harmful molecules such as nitrates and carbon dioxide to more valuable and less deleterious compounds, in order to cast light onto the mechanism of the reaction to achieve an efficient and…

Twenty years from now, the world population is estimated to be around 8.7 billion people, compared to the current 7.3 billion. In combination with the improvements in living standards and the corresponding growth in consumption, this will result in an enormous increase in the demand for food, consumables,…

Promotor: H.W. Lenstra

Promotor: M.T.M. Koper, Co-Promotor: L.B.F. Juurlink

Effectiveness and Side-effects.

Before the large scale use of renewable energy sources can be implemented in our society, the storage of electrical energy needs to be tackled. Storage the energy as hydrogen via the reduction of protons is a good option.

Harm reduction in practice: a comparative analysis of the Dutch and Brazilian approach towards drug users.

This thesis has shed light on some of the ways in which the local electrolyte composition can differ from the bulk and how these changes in the local reaction environment can determine the activity and/or selectivity of two important electrocatalytic reactions, namely, electrochemical CO2 reduction…

With the energy transition toward a renewable energy supply and a CO2-neutral economy, electrification of the energy system is rising in importance, which leads to the challenge of long-term storage of renewable electricity.

This thesis focuses on the synthesis, characterization and performance towards CO2 electroreduction of mono and bi-metallic particles based on p-block metals

The electrochemical oxygen reduction reaction (ORR) is an essential half-reaction for the utilization of hydrogen as a sustainable fuel, via the conversion of hydrogen to electrons and protons facilitated by the ORR. In the most common fuel cells, the ORR is requires high loadings of non-abundant platinum…

The goal is to reduce single use coffee cup use both at the university cafés and cofee machines.

Promotor: S.J. Edixhoven, A. Iovita

This dissertation provides a formal description of the relationship between diatopic/diachronic micro-variation and phonologization through analysis of the phonetic/phonological properties of unstressed vowel reduction and vowel insertion in two Northern Italian dialects.

Promotor: Prof.dr. A. Achucarro

Human civilization consumes a huge amount of fossil fuels, which has resulted in an atmospheric CO2 level which has not been higher in over 800 millennia.

A full overview of CASC PhD theses.

This work describes several studies into the electroreduction of carbon dioxide (CO2RR), both regarding mechanistical aspects and catalyst stability considerations. Mechanistic insights into carbon-carbon bond formation on a silver catalyst are described in Ch 2, were we find an acetaldehyde-like surface…

Chapter 1,contains the numerical verification of the Birch and Swinnerton-Dyer conjecture for hundreds of Jacobians of hyperelliptic curves of genus 2, 3, 4 and 5.

The mechanism of the electrochemical reduction of dioxygen by a mononuclear pyridylalkylamine copper complex was investigated (see picture). It was shown that in neutral aqueous solution dioxygen undergoes stepwise reduction, wherein hydrogen peroxide plays a key role. The rate constants determined…

Marc Koper’s research focuses on electrocatalysis and electrochemical surface science for sustainable energy and chemistry. Reactions of interest are the redox reactions of the oxygen/hydrogen cycle (water oxidation, hydrogen evolution), the carbon cycle (reduction of carbon dioxide, oxidation of small…

Electrocatalysis allows for storing electricity or converting it into chemical bonds, producing chemical building blocks and fuels using renewable resources.

Can we use indigenous microbial rice communities to reduce methane production in agricultural settings?

Research at the Catalysis and Surface Chemistry group is comprised of the following research themes:

Source: Journal of Investigative Dermatology, Volume 135, pp. S59-S59 (2015)

Following the Beirut explosion, BBC's podcast series The Foodchain explores the chemical that caused the blast: ammonium nitrate. A compound that is widely used to produce fertilizer. Professor of Environmental sustaibability Jan Willem Erisman tells about the effects of nitrogen on the environment.

Fearing a trade-off with economic growth, countries feel discouraged to cut their CO2 emissions. But do the two really not go together? Environmental scientist Ranran Wang and her colleagues investigated the relationship between economic growth and CO2 emissions in 73 countries from 1970 to 2016. Wang:…

The transition to new and renewable energy sources should be completed by 2050. Researchers in various disciplines at Leiden University are conducting unique research that will help us make this transition and reduce CO2 emissions.

It may well be possible to remove nitrate from polluted groundwater and at the same time produce ammonia in a sustainable way, according to PhD candidate Phebe van Langevelde and Professor Marc Koper of the Leiden Institute of Chemistry in Joule on 26 January. Together with a German colleague, they…

Artificial photosynthesis has recognised potential to produce green and sustainable fuels from earth-abundant resources such as water, carbon dioxide (CO2), and sunlight.

Greenhouse gasses in the atmosphere and fertilizers in the groundwater have negative consequences for our environment. With an electrochemical process they can be transformed to more valuable and useful substances like fuel and alcohol. Chemistry PhD candidate Elena Perez Gallent discovered how this…

Promotors: Prof.dr. E. Bouwman, Prof.dr. E. Drent

The Dutch Ministry of Finance says that new rules have significantly reduced tax avoidance via 'transit country' the Netherlands. Jan Vleggeert, Professor of Tax Law, has voiced his reservations about this claim in the media.

Molecular complexes can be used as electrocatalysts for oxygen reduction, water oxidation, and/or hydrogen peroxide production.

By reforming agriculture in targeted areas, we can protect the Natura 2000 areas much more effectively. This is what Jan Willem Erisman of Leiden University and Ton Brouwer of Gispoint consultancy write in a new report. They have created a special, nitrogen map of the Netherlands that shows the areas…

PhD defence

Multicopper oxidase, laccase, can efficiently reduce oxygen to water and are mostly used in the enzymatic biofuel cells.

In this thesis, we consider various (electro)chemical phenomena at surfaces and nanoparticles and their underlying atomistic processes, which we studied using first-principles methods such as density functional theory.

Bicarbonate buffer is largely found in nature due to its ability to regulate pH variations around neutral values. As the pH changes, so does the speciation of the buffer.

This dissertation focused on computational methods based on first principles calculations using the Density Functional Theory (DFT) framework. Emphasis was laid on affordable methods that can provide a tradeoff between computational expense and accuracy.

Cultural Anthropologist Jasmijn Rana argues in the opinion piece ''Black', 'white', or 'of colour' is not about purity' in the Leiden University Weekly Mare to use uneasiness about being reduced to skin colour and gender to fight racism.

Researchers at the Leiden University Medical Centre (LUMC) have managed to culture human heart muscle cells on a massive scale. This is an exceptional achievement because it is very difficult to replicate heart muscle cells outside the body. Using a special technique, the researchers have now created…

Opponents of drastic nitrogen measures argue that the nitrogen calculation model is not reliable enough. Nitrogen professor Jan Willem Erisman: 'It is now much more important to discuss the choices we make on the basis of the outcome. The differences are much bigger than the uncertainties in the mod…

Materials balances have been used in the recent past for the analysis of substance oriented environmental problems and the formulation of measures for environmental policy. In this study an integrated tool, based on the materials balance principle, has been developed for the analysis of both environmental…

Leiden University is working on a green, circular campus, with a significant reduction in energy consumption by 2050 as its goal, as elaborated in the Route Map Energy Transition Buildings, published in 2022.

Assuming everywhere good reduction we generalize the class number formula of Taelman to Drinfeld modules over arbitrary coefficient rings.

The thesis describes experimental steps towards reduction of friction on the macroscopic scale by scenarios of thermo- and superlubricity well-known on the nanoscale.

The research described in this thesis focused on the preparation of S/N functionalized carbene ligands and their transition metal complexes, and the exploration of their application as electrocatalysts for proton reduction.

Direct radiocarbon dating of human remains is crucial for the accurate interpretation of prehistory. Yet given the scarcity of prehistoric human remains, direct dating is often too destructive for important fossils. The reduction of sample size necessary for dating bone is therefore of great interest…