Understanding and designing molecules and materials for societal sustainability issues – that is what Chris Slootweg's research group is focusing on. Chemistry in society now mainly follows a linear model, where a product is produced, used, and then it becomes waste. With the current energy transition, the demand for batteries, wind turbines and solar cells is growing. Slootweg: 'If we continue to use them linearly, just like fossil fuels, then in addition to carbon waste, we will also have waste from all other elements in chemistry. That is absolutely not sustainable.'

Circular Chemistry

Slootweg therefore sees an essential role for chemistry within the circular economy. Circular economy means that existing materials and products are reused and recycled for as long as possible, which particularly limits waste. To implement this in chemistry, Slootweg has introduced the concept of “circular chemistry”, in which renewable raw materials can be used continuously.  

To achieve this, Slootweg emphasizes that the design of the products is crucial. 'For example, how a Dopper is made is not the most important thing in the circular economy. The most important thing is that you can reuse it more than a thousand times. So that focus on the product as a central vehicle in the cycle is really important.' That is why the focus of his research group is also on the (re)design of products. This involves a lot of technology.

AI and machine learning

Technology is first and foremost used for the fundamental research itself. An example of this is the use of AI and machine learning to design new molecules and materials.  

Slootweg explains: 'At the moment it is still very difficult to sketch a specific molecule or material and then predict its function, circularity and biodegradability. We can't do that yet. Technology is of great value, so that we can do this better and better.'  

Applying in society

On the other hand, Slootweg's research group develops technologies itself to apply the research in society. The demand for sustainable technologies is greater than ever due to climate challenges, the nitrogen problem, and the energy and materials transition. Fundamental knowledge in the field of sustainability can lead to new solutions for these social challenges.  

To develop this, according to Slootweg, it is important to first look at, for example, the energy transition and determine what knowledge is lacking. This can then be traced back to new research questions. 'I call that fundamentally applicable research, where the application is clear, but not how it works and what the ideal product looks like. It is appropriate for the universities to answer these knowledge questions. I think at the UvA we will make an even greater impact with this.'  

Hydrogen storage

Slootweg is currently mainly conducting research into hydrogen and hydrogen storage. For the energy transition, hydrogen must be produced, stored and used cleanly. The Port of Amsterdam aims to import one million tons of hydrogen by 2030. 

But what kind of hydrogen carriers can be widely used? The research group is currently working on several hydrogen carriers that can easily release hydrogen. They mainly focus on the design and optimization of the carrier so that it can be recycled more easily.

Recycling phosphate

The research group has also developed a method to recycle phosphate, an essential fertilizer. Fertilizers containing phosphate currently end up in the sewer or surface water as waste. Slootweg: 'You want to be able to recover and recycle phosphates, and thus help solve the waste problem, and at the same time reduce dependence on fossil phosphate. That's a win-win.' The patented technology that Marissa de Boer, Bas de Jong, and Chris Slootweg have developed has led to the spin-off company SusPhos.  

Future impact

According to Slootweg, the biggest impact that the research group can make is that their ideas, vision and projects can contribute to the circular economy, so that no waste mountains are created, but renewable raw materials can be used continuously.  

Slootweg: 'The concept of circular chemistry is now being taken up quite widely. I like to see that, not only because I started it and I thought it was important, but you see that others also share that opinion. That's great, because you can't improve the world alone. You need more people for that.'