The birth of a chemical bond (Day 282)

I am regularly fascinated by the work of colleagues who focus on fundamental chemical engineering science.  They deepen the understanding of our discipline and they can often help to explain the world that we live in.

This illustration shows atoms forming a tentative bond, a moment captured for the first time in experiments with an X-ray laser at SLAC National Accelerator Laboratory. The reactants are a carbon monoxide molecule, left, made of a carbon atom (black) and an oxygen atom (red), and a single atom of oxygen, just to the right of it. They are attached to the surface of a ruthenium catalyst, which holds them close to each other so they can react more easily. When hit with an optical laser pulse, the reactants vibrate and bump into each other, and the carbon atom forms a transitional bond with the lone oxygen, center. The resulting carbon dioxide molecule detaches and floats away, upper right. The Linac Coherent Light Source (LCLS) X-ray laser probed the reaction as it proceeded and allowed the movie to be created.

Image Credit | SLAC National Accelerator Laboratory
This illustration shows atoms forming a tentative bond, a moment captured for the first time in experiments with an X-ray laser at SLAC National Accelerator Laboratory.

An international group of researchers at the US Department of Energy’s SLAC National Accelerator Laboratory has caught my eye. They’ve used an X-ray laser to capture the first glimpse of two atoms forming a bond, and thus becoming a molecule.

The idea that we can actually observe a chemical bond at the point of formation was long thought to be impossible. So, I can’t stress  enough the profound impact that this work could have on our understanding.

The research will help to clarify how chemical reactions take place, which in turn, can help us design reactions that generate energy, create new products and fertilise crops more efficiently.

Anders Nilsson, a professor at the SLAC/Stanford SUNCAT Center for Interface Science and Catalysis, US, and at Stockholm University, Sweden,  who led the research said: “This is the very core of all chemistry. It’s what we consider a Holy Grail, because it controls chemical reactivity. But because so few molecules inhabit this transition state at any given moment, no one thought we’d ever be able to see it.”

This work was recently published in the leading journal Science: Probing the transition state region in catalytic carbon monoxide oxidation on ruthenium, and was undertaken in a collaborative project involving the SUNCAT Center, Stockholm University, LCLS, Helmholtz-Zentrum Berlin for Materials and Energy, University of Hamburg, Center for Free Electron Laser Science, University of Potsdam, Fritz-Haber Institute of the Max Planck Society, DESY and the University of Liverpool.

Anders explains his work and why it matters in more detail in this YouTube video. It’s well worth watching.

Anders and the team studied the neutralisation of carbon monoxide reaction – the reaction that takes place in the catalytic converter on a car. The reaction takes place on the surface of catalyst, which holds the carbon monoxide and oxygen atoms next to each other facilitating easier formation of carbon dioxide.

Carbon monoxide and oxygen were attached to the surface of a ruthenium catalyst, and reactions were triggered with a pulse from an optical laser. The pulse heated the catalyst to 2,000 ºK (That’s over 1,700ºC) causing the attached molecules to vibrate; increasing the chance that they knock into each other and bond.

Anders and the other researchers were able to observe this happening by using X-ray laser pulses, which are able to detect changes in the arrangement of an atoms’ electrons (a sign of bond formation) occurring in femtoseconds, or in a quadrillionth of a second.

The group involved in this research is already starting to apply this work to other catalytic reactions that generate important chemicals.

Chemical Engineering Matters tells us that we must never lose sight of the fundamental science that underpins our discipline. This work offers the potential to revolutionise our approach to chemical reaction engineering and I find it truly exciting.

Congratulations to everyone involved.

One thought on “The birth of a chemical bond (Day 282)

  1. This fundemental science will help chemical engineering once we learn how to use it for optimisation and design of reactors.

    If it helps better understand what is happening in reactions it will be major step forward. A chemical engineer working in the pharmaceutical industry I have often found it frustrating that the chemist I have worked with do not really understand the chemistry. So it has not been possilbe to make use of the any of the standard chemical engineering tools.


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