Electrochemical promotion of catalysis for pollution control

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Reactions involving the catalytic conversion of nitrogen oxide (NOx), hydrocarbons, volatile organic compounds and carbon monoxide are of major environmental importance for the removal of toxic emissions from both stationary and automotive sources. Toxic compounds can be converted to harmless non-pollutants using heterogeneous catalysis. The reduction of nitrogen oxides by light hydrocarbons in the presence of excess of oxygen, typical of the exhaust of lean-burn and Diesel engines, presents a great technological challenge. Conventional catalysts show several disadvantages, such as high cost, short life time, and fail to control their activity during the catalytic process. The recently discovered phenomenon of Electrochemical Promotion of Catalysis (EPOC) combined with classical heterogeneous catalysis could be applied in order to overcome some of the above mentioned problems. The controlled variation in the catalyst-electrode potential of metal or metal oxide films supported on solid electrolytes is responsible for considerable changes in catalytic activity and selectivity. It has been demonstrated that electrochemical promotion is not limited to any particular electrolyte, conductive catalyst, or type of reaction. The major obstacles towards commercialization of EPOC are the lack of efficient catalysts and reactor design. The objective of the proposed research program is to develop efficient system devices for the removal of the toxic pollutants (NOx, hydrocarbon, carbon monoxide, etc.) from Diesel and lean-burn automobile exhausts using electrochemical promotion. The overall goal in the short to medium term is to design nano-structured catalysts of defined size and structure, and their application to NOx reduction. The long term objective is to establish a comprehensive understanding of the electrochemical promotion with nano-structured catalysts. The significant output of this interdisciplinary research will answer many fundamental questions in heterogeneous catalysis and lead to a new stage of nano-sized catalytic systems for air pollution prevention.