Highly Efficient Catalysts of AuPd Alloy Nanoparticles Supported on 3D Ordered Macroporous Al2O3 for Soot Combustion

Abstract The catalysts of Au−Pd bimetallic nanoparticles with different Au/Pd ratios supported on 3DOM Al 2 O 3 were synthesized by micropores‐diffused reduction (MDR) method. Compared with supported monometallic Au or Pd catalysts, supported bimetallic Au−Pd nanoparticle catalysts, especially Au 2 ‐Pd 2 /3DOM Al 2 O 3 , show higher catalytic activity for soot combustion due to good synergetic effects between gold and palladium. Au/Pd ratio has a significant influence on the chemical states and size of bimetallic nanoparticles. The co‐presence of Au is favorable for the formation of metallic Pd instead of PdO. And the size of Au−Pd bimetallic nanoparticles gradually decreases with increasing Au/Pd ratio. The effect of water in the reaction atmosphere and SO 2 ‐presulfurization of the catalyst on the activity is also studied. It is unexpected that Au 2 ‐Pd 2 /3DOM Al 2 O 3 catalysts with SO 2 ‐presulfurization has higher catalytic activity than the fresh catalysts. The increased activity is related to the formed surface aluminum sulfate and enhanced acidity.