The poisoning effect of PbO and PbCl₂ on CeO₂-TiO₂ catalyst for selective catalytic reduction of NO with NH₃ was investigated and compared. Both Pb species could deactivate the CeO₂-TiO₂ catalyst and PbO had a stronger poisoning effect than PbCl₂. From the characterization results of BET, XRD, XPS, NH₃-TPD and H₂-TPR, it was concluded that the more serious deactivation by PbO could be ascribed to smaller BET surface area, fewer surface Ce³⁺ and chemisorbed oxygen, stronger interaction between PbO and CeO₂-TiO₂ catalyst, lower redox properties and surface acidity. The in situ DRIFT study results revealed that the NH₃-SCR reaction over CeO₂-TiO₂ catalyst was governed by both E-R and L-H mechanisms, which wasn’t changed over the Pb-poisoned samples. The greater loss of Brønsted acid sites attributed to fewer surface Ce³⁺ and more serious inhibition of NO oxidation to NO₂ due to fewer surface chemisorbed oxygen were two key factors responsible for more serious deactivation by PbO. Furthermore, the presence of Pb species inhibited the NH₃ adsorption on the Lewis acid sites, aggravating the deactivation of CeO₂-TiO₂ catalyst.

研究并比较了PbO和PbCl ₂对CeO ₂ -TiO ₂催化剂的毒害作用，该催化剂对NH ₃选择性催化还原NO具有重要作用。两种Pb都可以使CeO ₂ -TiO ₂催化剂失活，并且PbO具有比PbCl ₂更强的中毒作用。从BET，XRD，XPS，NH ₃ -TPD和H ₂ -TPR的表征结果可以得出结论，PbO的更严重失活可以归因于BET表面积更小，表面Ce ³⁺和化学吸附的氧更少，更强PbO与CeO ₂ -TiO ₂之间的相互作用催化剂，降低氧化还原性能和表面酸度。该原位DRIFT研究结果表明，NH ₃以上的CeO -SCR反应₂ -TiO ₂催化剂通过两个ER和LH的机制，这是不超过铅中毒采样发生变化支配。较少的表面Ce ³⁺引起的布朗斯台德酸位点更大的损失以及由于较少的表面化学吸附的氧而导致的NO氧化为NO _2的抑制作用更为严重，这是导致PbO严重失活的两个关键因素。此外，Pb物种的存在抑制了路易斯酸位点上的NH ₃吸附，加剧了CeO ₂ -TiO ₂的失活。 催化剂。