Theme C – Syngas Production & Catalysis
The third Theme in the Programme deals with the most common area of CCU research, converting the CO2 into a useful product, in our case, fuel. As outlined in the original proposal, we are examining two routes for this conversion. The first via syngas and the second by direct catalysis. In Sub Programmes 5 & 6, we are looking at production of syngas which will require subsequent reaction schemes such as Fischer Tropsch (FT) to arrive at a final useful product. Direct catalysis would not have this disadvantage but no catalysts of any significant level of commercial development currently exist so that our work here is exploratory and conducted, to a significant degree, in silico. The work reported in SP1 & 2 has demonstrated the potential damage that FT can do to the sustainability performance CO2 to fuel process. Future work will, therefore, search for low temperature and pressure alternatives to FT.
In SP5 we are considering electrocatalytic reduction to CO and/or syngas by use of a high temperature solid electrolyte cell (SOEC). Such cells are well studied for fuel cell applications but their behaviour as electrolysis cells is much less understood and there is little work on cells specifically optimised for electrolysis. We are aiming to enhance fundamental understanding by means of an advanced suite of techniques for in situ structural determination and examination of the intermediate species present on the electrode and electrolyte. Molecular modelling is being used alongside these techniques to inform experiments and deepen understanding. In addition, we are making advances in cell architecture through material and morphology changes both for electrodes and electrolytes.
At the time of the proposal, the work of SP6, plasma reduction of CO2, was little considered and had a very small literature, particularly from the UK. In the intervening three years, the idea of plasma reactors for CCU purposes has become mainstream. We retain our focus on those plasma geometries most likely to be commercially exploitable, in particular packed beds of ferroelectric/catalytic material and wire in tube corona discharge reactors. The latter are chosen because of their strong resemblance to Electrostatic precipitators widely used to remove particles from high volume flow gas streams in industries such as cement and power generation.
In SP7 we seek to develop catalysts that work at significantly lower temperatures by careful design using directed assembly principles. The modelling will be designed to predict catalysts which can operate under moderate conditions and obtain families of the products selectively. By incorporating the catalysts in a well-designed ionic liquid capture agent operating at the boundary between physi- and chemisorption we aim to use the support to amplify the reduction in activation energy.