Are you influenced by neighbors? As well as nanoparticles in the catalyst. A new study from Chalmers, published in the journal Advances in Science and Natural Communication, reveals how close neighbors judge how well nanoparticles work on the catalyst.
“The long-term goal of the study is to identify ‘super-particles’, to contribute to a more efficient catalyst in the future. To utilize better resources than at present, we also want as many particles as possible to actively participate in catalytic reactions at the same time. same, “said research leader Christoph Langhammer at the Department of Physics at Chalmers University of Technology,
Imagine a large group of neighbors huddled together cleaning the public courtyard. They set about their work, each contributing to a group effort. The only problem is that not all of them are equally active. While some work hard and efficiently, others walk, talk and have coffee. If you only see the end result, it will be difficult to know who is working the most, and who is simply relaxing. To judge that, you need to monitor every person throughout the day. The same applies to the activity of metal nanoparticles in catalysts.
Possibility to learn which particles do what, and when
In catalysts some particles affect as effectively. Some particles in the crowd are effective, while others are not active. But the particles are often hidden in different ‘pores’, such as in a sponge, making it difficult to detect.
To be able to see what is really happening in the catalyst pores, researchers from Chalmers University of Technology isolated a small amount of copper particles in a transparent glass nanotube. When several are collected together in a small gas-filled pipe, it is possible to study which particles do, and when, in real conditions.
What happens in a tube is that the particles come into contact with a mixture of gases that flow from oxygen and carbon monoxide. When these substances interact with the surface of copper particles, carbon dioxide is formed. The same reaction occurs when exhaust gases are purified in a car catalytic converter, except that platinum, palladium and rhodium particles are often used to convert to toxic carbon monoxide, instead of copper. But these metals are expensive and scarce, so researchers are looking for more efficient resource alternatives.
“Copper can be an attractive candidate for oxidizing carbon monoxide. The challenge is that copper tends to change itself on its own, and we need to be able to measure the oxidation that states copper particles when most active inside the catalyst. With our nanoreactors, which mimic holes in real catalysts. , now it can be done, “said David Albinsson, Postdoctoral researcher at the Department of Physics in Chalmers and the first author of two recently published scientific papers on Natural Science and Natural Communication.
Optimized neighborly cooperation can save resources
Anyone who has ever seen an old copper roof or sculpture will recognize how the reddish-brown metal turns green after contact with air and pollutants. The same thing happens with copper particles in the catalyst. So it is very important that they work together in an effective way.
“What we have shown so far is that the oxidation state of particles can be dynamically affected by nearby neighbors during the reaction. The hope is that we can ultimately save resources with the help of neighbors that are optimized in the catalyst,” said Christoph Langhammer, Professor at the Department of Physics at Chalmers ,
“Copper catalysis under operando – unites the gap between single probe nanoparticles and catalyst-beds” by David Albinsson, Astrid Boje, Sara Nilsson, Christopher Tiburski, Anders Hellman, Henrik Ström and Christoph Langhammer, 24 September 2020, Natural Communication,
DOI: 10.1038 / s41467-020-18623-1
“Detection of operando dynamics of single nanoparticle activity in pore catalyst material model” by David Albinsson, Stephan Bartling, Sara Nilsson, Henrik Ström, Joachim Fritzsche and Christoph Langhammer, 19 June 2020, Advances in Science,
DOI: 10.1126 / sciadv.aba7678