Hyperpolarised, Gas-phase Magnetic Resonance Imaging of a non-flow through Filter.

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Understanding and improving the design and operation of combined selective catalytic reduction and filtration monoliths, for reducing emissions from engines used in static and transport applications. Particular focus will paid to the manufacturing process and the impact on the performance of the filters. This includes looking at the spatial distribution of the washcoat, which contains the active SCR catalyst, within the channels and walls of the porous filter support block. The spatial distribution is critical as it affects the exhaust gas flow through the filter, and, thence, the pressure drop of the system, the filtration efficiency, and the accessibility and, thus, activity, of the catalyst. In order to probe the gas flow pattern in the support channels, and the permeation of gas through the walls, this project will develop and use novel gas phase NMR and magnetic resonance imaging (MRI) methods using hyperpolarised (HP) gases. This work will look at the potential for bypassing of the SCR catalyst caused by an inhomogeneous distribution of washcoat. HP Xe MRI will also be used to look at the influence of channel surface roughness (eg due to washcoat deposits) on the velocity field and wall shear stress, as this impacts the particle margination effect for the soot particles being filtered. This project will also include new MRI technique development. The project will also give the opportunity to spend time in the Johnson Matthey company development labs working on the washcoat delivery systems for the filters, and the development of the SCR catalyst-washcoat formulation. This will give the student the opportunity to work on the whole causal progression from washcoat formulation, to washcoat distribution, to filter flow characteristics and performance.