Electrochemical Promotion Of Catalysis (EPOC) or Non-faradaic Electrochemical Modification of Catalytic Activity (NEMCA)
Phenomenon that refers to the very pronounced and reversible enhancement in catalytic activity and selectivity of metal or metal-oxide catalysts deposited on solid electrolytes caused by application of small electrical currents or potentials
Burning fuels either fossil (natural gas, oil, diesel etc.) or fuel produced from sustainable sources (bio-fuel), generates pollutants like nitrogen oxides (NOx), which need to be destroyed before they can reach the atmosphere. Two types of NOx sources can be distinguished due to human activities: stationary and automotive emissions. The first are attributed to the factories producing nitrous compounds or to industries where the chemical or thermal processes lead to oxidation of the nitrogen contained in air.
Reduction of pollutant emissions present in the exhaust of lean-burn and Diesel engines has attracted great scientific interest due to a recent strategy to improve fuel efficiency (and thus reduce overall emissions). However, the high oxygen concentration hinders the NOx reduction reaction in the catalytic converter, making necessary the implementation of a transient NOx storage process and continuous shifting of the engine operation between lean-burn and rich-burn conditions. The phenomenon of Electrochemical Promotion of Catalysis combined with classical heterogeneous catalysis could be applied for catalyst regeneration and activation during NOx reduction in excess of oxygen.
Efficient, compact and intelligent reactor designs must be utilized to make an electrochemically promoted reactor commercially attractive
Evolution of cell configurations for EPOC
(Group of Electrochemical Engineering - GGEC, EPFL)
Rh catalyst (40 nm) sputtered Rh catalyst (40 nm) sputtered on TiO2
on Yttria-Stabilized Zirconia (YSZ)