A catalyst is a substance that reduces the energy input required for a reaction – many industrial processes use a catalyst to make them feasible and economic.
There are many types of catalysts for different applications, and zeolite catalysts are used commercially to reduce the negative effects of exhaust fumes from diesel engines and produce fuels more efficiently. Catalysts can be studied with light, in a process called spectroscopy, to help understand how they work.
My PhD research has greatly benefitted from the use of synchrotron radiation. It helped me to gain detailed mechanistic insight into how the zeolite catalyst works. To date, I have completed four scientific visits at the Diamond Light Source, which is the UK’s national synchrotron facility, located in Oxfordshire.
Diamond Light Source is the UK’s national synchrotron science facility, located in Oxfordshire. It was opened in June 2014 to support industrial and academic research.
What is a synchrotron?
Diamond Light Source. Image credit: Diamond Light Source
A synchrotron generates very bright beams of light by accelerating electrons close to the speed of light and bending them through multiple magnets. The broad spectrum of light produced, ranging from X-rays to infrared (IR) light, is selectively filtered at the experimental laboratories (beamlines), where a specific region of the electromagnetic spectrum is utilised. My work uses the IR part of the electromagnetic spectrum. IR light has the right energy to probe bond stretches and deformations, allowing molecular observations and determination.
A highlight from last year has been attending a joint beamtime session with Prof Russell Howe and Prof Paul Wright at Diamond’s IR beamline (MIRIAM, B22). The MIRIAM beamline is managed by Dr Gianfelice Cinque and Dr Mark Frogley.
The synchrotron enables us to capture the catalyst in action during the methanol to hydrocarbons reaction. The changes in the zeolite hydroxyl stretches we observe correlate with the detection of the first hydrocarbon species downstream.
A cartoon illustration of the evolution of the zeolite hydroxyl stretch band during the methanol to hydrocarbons process. Image credit: Ivalina Minova
What is it like researching at Diamond?
My access to Diamond is typically spread over six-month intervals. To secure beamtime, we have to submit a two-page research proposal. This is assessed by a scientific peer review panel and allocated three or four days to complete the proposed experiments.