A model catalyst for natural gas vehicles (NGVs), Ce-Pd/Al₂O₃ (Pd-C/A), was modified with P. The chemical properties of the catalyst were affected significantly by P modification. The P-modified catalyst (Pd-CP/A) showed better reducibility, more Pd step sites and surface PdO species. The catalysts were tested for the removal of CH₄, CO and NO under simulated stoichiometric NGVs exhaust conditions. Compared to Pd-C/A, Pd-CP/A showed enhanced activity for the removal. The time on stream (TOS) results further demonstrated that the P additive was capable to stabilize Pd species in the form of active PdO, resulting in significantly improved durability for Pd-CP/A. The electronic interaction of Pd with P was found to contribute to the stabilization. The P additive could also considerably suppress the formation of PdO₂ which is much less active for the reactions. Our work may provide a general approach to design highly efficient catalysts for NGVs emission control.

用P对天然气汽车（NGVs）的模型催化剂Ce-Pd / Al ₂ O ₃（Pd-C / A）进行了改性。P的改性对催化剂的化学性能有很大的影响。P改性催化剂（Pd-CP / A）表现出更好的还原性，更多的Pd台阶位和表面PdO种类。测试了催化剂中CH ₄的去除，CO和NO在模拟的化学计量NGV排气条件下。与Pd-C / A相比，Pd-CP / A显示出更高的去除活性。生产时间（TOS）结果进一步证明，P添加剂能够以活性PdO形式稳定Pd物质，从而显着提高了Pd-CP / A的耐久性。发现Pd与P的电子相互作用有助于稳定。P添加剂还可以显着抑制对反应活性低得多的PdO ₂的形成。我们的工作可能会为设计用于NGV排放控制的高效催化剂提供一般方法。