Key Words:Catalytic oxidation;Catalyst activity - Diesel engines - Ion exchange - Magnesium compounds - Metal nanoparticles - Oxidation - Petroleum prospecting - Platinum - Silicate minerals - Temperature - Zeolites

Abstract:With the appearance of the low temperature combustion (LTC) diesel engines, diesel oxidation catalyst (DOC) becomes more and more important in removing the CO and hydrocarbons (HC) emitted from LTC diesel engines, especially in cold start-up process. Herein, metal species-modified hierarchically porous zeolites BEA (H-BEA) containing 0.8 wt% Pt have been synthesized by an ion-exchange and subsequent deposition-reduction method. It is found the obtained catalyst PtFeMg/H-BEA shows super catalytic activity, high water and sulfur resistance, i.e., the temperatures T<inf>90</inf> are as low as 95 °C and 225 °C in the CO and C<inf>3</inf>H<inf>8</inf> oxidation, respectively. It is believed that the strong interaction between Pt species and metal Fe, Mg-modified zeolite H-BEA is conductive to the CO and C<inf>3</inf>H<inf>8</inf> catalytic oxidation. Further integrated into commercial cordierite honeycomb ceramics substrates, the obtained monolithic DOC still exhibits an excellent catalytic activity and anti-aging performance even under high velocity and multiple reaction atmosphere, indicating its promising prospects in the practical application. Besides, FTIR results indicate that there are two forms of Pt species: Pt atom in the zeolite BEA framework and metal Pt nanoparticles/clusters dispersed on the surface of BEA, which jointly promotes the adsorption and oxidation of CO and C<inf>3</inf>H<inf>8</inf>.<br/> © 2019 Elsevier Inc.

Volume:379

Issue:无

Translation or Not:no