BaKCo/CeO2 catalysts for diesel soot and NOx abatement

Introduction Soot particles and NOx are the main pollutants from diesel engines. Good alternatives to abate these contaminants are the use of catalytic filters, which burn the soot particles, and NOx traps which adsorb the NOx during normal operation and released them during reduction cycles [1]. We recently studied BaK/CeO2 catalysts for this application[2]. Barium plays the role of NOx adsorbent, and K and CeO2 are a good combination to oxidate soot, due to the high K movility, improving the soot-catalyst contact, and the redox behavior of CeO2. The addition of Co improved the behavior of the catalyst as a NOx trap, since the nitrocompounds formed upon treatment with NOx resulted to be less stables as compared to barium nitrate formed on BaK/CeO2 [3]. In this work, the stability of BaKCo catalysts was studied, including thermal stability and stability in presence of water, NO + O2 and SO2, all these compounds being present in the diesel exhaust atmosphere. The influence of Co precursors on the catalyst soot combustion activity, stability and behavior as a NOx trap was also analyzed.