Greener Emissions with PdPt Catalysts | Johnson Matthey, University of Reading & Diamond Light Source

The challenge

The hunt for viable green alternatives to traditional petrol and diesel engines has led a move towards natural gas engines, which produce less carbon dioxide emissions.

But natural gas engines pose other problems due to unburnt methane (a potent greenhouse gas) in the exhaust feed. So scientists at Diamond, Johnson Matthey – a global leader in sustainable technologies - and the University of Reading, have been researching ways to improve catalysts to convert residual methane into more environmentally friendly products.

The solution

A team from Johnson Matthey and the University of Reading used advanced characterisation techniques to study the reactions taking place at the atomic level under real operating conditions. They performed in situ near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) studies, using Diamond’s beamline B07-C VerSoX at Diamond, on a series of palladium and platinum on alumina (PdPt/Al₂0₃) catalysts with different ratios of Pt to Pd. This technique enabled them to identify the elements present on the surface of the material and their chemical state under reaction conditions. They observed significant changes in the oxidation state of Pd depending on the reaction conditions and the concentration of Pt.

The research showed that wetter conditions led to a smaller degree of Pd oxidation at all temperatures studied. Pd catalysts doped with 1 wt% Pt were the most active at a lower temperature range, under both dry and wet conditions. However, in very oxygen-rich reaction mixtures there was less of a clear benefit to adding Pt.

The benefits

A team from Johnson Matthey and the University of Reading used advanced characterisation techniques to study the reactions taking place at the atomic level under real operating conditions. They performed in situ near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) studies, using Diamond’s beamline B07-C VerSoX at Diamond, on a series of palladium and platinum on alumina (PdPt/Al₂0₃) catalysts with different ratios of Pt to Pd. This technique enabled them to identify the elements present on the surface of the material and their chemical state under reaction conditions. They observed significant changes in the oxidation state of Pd depending on the reaction conditions and the concentration of Pt.

The research showed that wetter conditions led to a smaller degree of Pd oxidation at all temperatures studied. Pd catalysts doped with 1 wt% Pt were the most active at a lower temperature range, under both dry and wet conditions. However, in very oxygen-rich reaction mixtures there was less of a clear benefit to adding Pt.

Understanding bi-metallic catalysts

Improving catalysts to provide greener emissions

The challenge

The solution

The benefits

Understanding bi-metallic catalysts

Improving catalysts to provide greener emissions

The challenge

The solution

The benefits

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