The selective catalytic reduction of NO with C₃H₆ and CO was investigated over platinum group metal (PGM; Pd, Rh, or Pt) supported on NbOPO₄. Rh/NbOPO₄ exhibits a lower light-off temperature of NO reduction to N₂ compared to Pd- or Pt-loaded NbOPO₄ catalysts and Rh/Al₂O₃ under stoichiometric conditions. Rh/NbOPO₄ shows superior catalytic activity for NO reduction to Rh/Al₂O₃ under a wide range of lean conditions. Propylene (C₃H₆) was partially oxidized to reactive aldehyde species on Rh/NbOPO₄, whereas less-reactive carboxylate species was generated and adsorbed on Rh/Al₂O₃. A highly dispersed Rh⁰ nanoparticles on NbOPO₄ was slowly oxidized by exposure to excess O₂, but Rh on Al₂O₃ was readily oxidized to less-active Rh₂O₃. The high activity of Rh/NbOPO₄ for C₃H₆ oxidation to reactive aldehyde species and the resistance of Rh⁰ against oxidation results in the enhancement of NO reduction activity in a slightly lean region.

研究了负载在NbOPO ₄上的铂族金属（PGM； Pd，Rh或Pt）对C ₃ H ₆和CO选择性还原NO的影响。在化学计量的条件下，与负载Pd或Pt的NbOPO ₄催化剂和Rh / Al ₂ O ₃相比，Rh / NbOPO ₄的NO还原成N _2的起燃温度更低。在多种稀薄条件下，Rh / NbOPO ₄对NO还原为Rh / Al ₂ O ₃表现出优异的催化活性。丙烯（C ₃ H ₆）在Rh / NbOPO上被部分氧化为反应性醛类_在图4中，反应性较低的羧酸盐种类被生成并吸附在Rh / Al ₂ O _3上。NbOPO ₄上高度分散的Rh ⁰纳米颗粒通过暴露于过量的O ₂缓慢氧化，而Al ₂ O ₃上的Rh容易被氧化为活性较低的Rh ₂ O ₃。Rh / NbOPO ₄具有高活性，可将C ₃ H ₆氧化成活性醛，Rh ^0具有抗氧化性，可在稀薄区域提高NO还原活性。