Preparation of alumina-supported gold-ruthenium bimetallic catalysts by redox reactions and their activity in preferential CO oxidation

Lean-burn engine technology offers improved fuel economy; however, the reduction of NOx during lean-operation continues to be a major technical hurdle in the implementation of energy efficient technology. Recently reported passive NH3-SCR system (PASS)– a simple, low-cost, and urea-free system – has the potential to enable the implementation of lean-burn gasoline engines; however, the system suffers from CO slips during extended rich operations. The slipped CO can be easily oxidized with supplemental oxygen feed over platinum group metal (PGM)-based catalysts; however the PGM-based catalysts simultaneously oxidize the generated NH3. This work focuses on the preparation of catalysts that can preferentially oxidize CO in the presence of NH3.