Electrocatalytic reduction of NOx on La(1-x)A(x)B(1-y)B(y)O(3-delta): evidence of electrically enhanced activity

Solid-state electrochemical cells can be used to sense and reduce NO from c ombustion exhaust gases. In the reduction process the products are N-2 and O-2. For these cells to be effective in fuel-lean combustion exhaust, catho de materials with high selectivity for NO vs. O-2 are necessary. Numerous c ompositions of La(1-x)A(x)B(1-y)B(y)'O3-delta (where A is Sr or Ba; and B a nd B' are transition metals) were investigated for heterogeneous catalytic activity and selectivity for NO reduction using temperature programmed reac tion (TPR). Ceramic cells using these materials as cathodes were fabricated and used to electrocatalyrically reduce NO in NO/He and simulated exhaust atmospheres. An enhanced electrocatalytic three-way activity for NO, reduct ion was demonstrated that increases the window of operation into fuel-lean conditions. (C) 2000 Elsevier Science B.V. All rights reserved.