CO₂ capture and utilisation is a priority research area due to the link of this greenhouse gas to climate change. Several industrial processes emit CO₂ to the atmosphere; however, instead of treating it as a waste and a contributor to climate change, CO₂ can be a valuable C1 feedstock to make chemicals and fuels.

A research goal of the Catalysis Engineering group (HIMS) is to convert CO₂ into useful chemicals. One bottleneck on the efficient conversion of carbon dioxide is that it is highly stable. This translates into high reaction temperatures (>600 °C), which limits the industrial application of thermocatalytic CO₂ conversion reactions. Researchers in the group actively work towards finding active, selective and stable catalysts that bring down the application costs of CO2 conversion.

Collaborative study

Researchers of the Self-Organizing Matter group (AMOLF) work on making complex and functional, yet beautifully shaped nanocomposites. They recently found that ion exchange can change the composition of these nanocomposites, allowing a large variety of compositions that inherit their sculpted architecture. Specifically, the nanocomposite’s composition can be tuned to nickel-, iron-, manganese- or cadmium salts, making them attractive for catalysis.

A collaborative study conducted by PhD students Hans Hendrikse (AMOLF) and Maria Ronda-Lloret (HIMS), under the supervision of Dr Wim Noorduin and Dr Raveendran Shiju, recently showed that these coral-like architectures are efficient catalysts for CO2 conversion. They tested a NiO/SiO2 composite in the dry reforming of butane, where butane and CO2 react to form syngas (a mixture of CO and H2). Syngas is a useful chemical mixture to produce a large variety of chemicals, such as hydrocarbons or alcohols through the Fischer-Tropsch synthesis.

Coral-like structures

The coral-like structures allow high metal contents while maintaining a small nanocrystal size and  a good contact between their components. This enhanced their interaction with the reagents, achieving high conversion and selectivity at relatively low temperature (400 °C). These coral-shaped catalysts outperform traditional catalysts at low temperatures: a conventional NiO supported on SiO₂ catalyst of similar metal content showed very low selectivity to syngas, while a conventional catalyst with lower metal content was inactive at 400 °C.

The team also explored other applications of these new materials.  For example, they synthesised shape-controlled magnetite (Fe₃O₄) nanocomposites that can be moved and reoriented using their magnetic properties. They also created electron-beam activated microscopic actuators by using the flexibility and the shrinking properties of the silica matrix.

This research, supported by the Vernieuwingsimpuls Vidi research program  (Shaping  up  Materials) and a NWO-NSFC grant, is now available as a communication in the international journal Advanced Materials

Publication details

Hans C. Hendrikse, Arno van der Weijden, Maria Ronda-Lloret, Ting Yang, Roland Bliem, N. Raveendran Shiju, Martin van Hecke, Ling Li, and Willem L. Noorduin: Shape-Preserving Chemical Conversion of Architected Nanocomposites, Adv. Mater., 2020, 2003999. DOI: 10.1002/adma.202003999

Read more

• Highlight in Nature: Presto chango: tiny particles get a chemical makeover but keep their shape
• Nature review materials: Nanocomposites keep in shape