Plasma catalysis

Plasma catalysis involves the use of plasma, a highly energized state of matter, to promote or initiate catalytic reactions. Plasma is a collection of charged particles, including electrons and ions, along with neutral particles, and it can provide high-energy species that can break chemical bonds and facilitate catalytic reactions. Plasma catalysis is employed in various applications, including environmental remediation and the synthesis of valuable compounds.

One common example of plasma catalysis is the conversion of methane (CH) to higher-value hydrocarbons or hydrogen. In the presence of a plasma, methane molecules are exposed to high-energy species, such as electrons and ions, generated in the plasma. These energetic species can break the strong carbon-hydrogen bonds in methane, initiating various chemical reactions. The result is the formation of a mixture of hydrocarbons, such as ethylene and acetylene, or the production of hydrogen.

PartCat has developed expertise in plasma integration in electrochemical ammonia production and thermal CO2 methanation. Through integration of plasma, the reaction catalytic intermediates are altered, changing the overall reaction pathway, and thus reducing required energy inputs to generate sustainable energy carriers.

Competitive advantage

  • PartCat combines expertise in nanoscale catalyst synthesis, reaction process design, and plasma technology to two key reactions: ammonia production and CO2 conversion
  • For ammonia production: utilisation of non-thermal plasma can generate NO3-, which is then electrocatalytically reduced to ammonia, a novel pathway for ammonia production only utilising water, air, and electricity
  • For CO2 methanation: utilisation of non-thermal plasma can enhance the dissociation of CO2 into reaction intermediates, which are then reduced to methane at lower temperatures compared to conventional thermal catalysis

Impact

  • Ammonia production can occur without the energy intensive Haber-Bosch process, while utilising renewable energy inputs, where the ammonia produced can be used as a hydrogen carrier, chemical feedstock, or directly as a fertiliser
  • Conversion of waste CO2 (e.g. contained in flue gas) into methane can be used as a carbon up-cycling process, which can occur at lower temperatures due the to incorporation of plasma

Successful applications 

  • Ammonia production utilising hybrid-plasma-electrolyser technology uses a low pressure (~10 bar) operation, and could reduce the energy input by >25% and carbon footprint by >90% compared with the conventional Haber–Bosch process
  • The yields of ammonia can be increased by ~3000 times when compared to highest yield obtained by electrochemical nitrogen reduction
  • CO2 methanation with an integrated plasma resulted in a CO2 conversion of 60% with a CH4 selectivity of over 97% at 150 °C, compared to a required temperature of 320 - 330 °C in conventional thermal catalysis

Capabilities and facilities 

  • A range of non-thermal plasma generating devices to generate plasmas including radio-frequency and arc discharge 
  • Custom designed electrochemical and thermal catalytic reactors which integrate plasma
  • Nanoparticle synthesis and characterisation techniques
  • Product detection capabilities (NMR, GC/MS, UV-Vis) and a wide range of electrocatalytic reactions