【摘要】 ＴｉＯ＿２、Ｌａ＿２Ｏ＿３和ＺｒＯ＿２以单层形式分布在ＳｉＯ＿２上制得了Ｐｄ催化剂。经４７３Ｋ（ＬＴＲ）及７７３Ｋ（ＨＴＲ）Ｈ＿２处理后，进行Ｈ＿２－Ｏ＿２滴定反应，测定催化剂对Ｈ＿２的吸附能力。结果表明，Ｐｄ／ＴｉＯ＿２／ＳｉＯ＿２，Ｐｄ／Ｌａ＿２Ｏ＿３／ＳｉＯ＿２及Ｐｄ／ＺｒＯ＿２／ＳｉＯ＿２的吸氢能力高于单一载体Ｐｄ催化剂的吸氢能力，说明ＳｉＯ＿２骨架经徐层氧化物的改性，Ｐｄ得到较好的分散。Ｐｄ与载体之间相互作用为：Ｐｄ／ＴｉＯ＿２＞Ｐｄ／Ｌａ＿２Ｏ＿３＞Ｐｄ／Ｔ１Ｏ＿２／ＳｉＯ＿２＞Ｐｄ／Ｌａ＿２Ｏ＿３／ＳｉＯ＿２＞Ｐｄ／ＳｉＯ＿２＝Ｐｄ／ＺｒＯ＿２＝Ｐｄ／ＺｒＯ＿２／ＳｉＯ＿２。ＴＰＲ、ＴＰＤ实验结果与Ｈ＿２－Ｏ＿２滴定的结果基本一致。ＴＰＤ的结果进一步证实，易于受Ｈ＿２还原温度影响的Ｐｄ／ＴｉＯ＿２、Ｐｄ／Ｌａ＿２Ｏ＿３催化剂改性为Ｐｄ／ＴｉＯ＿２／ＳｉＯ＿２、Ｐｄ／Ｌａ＿２Ｏ＿３／ＳｉＯ＿２后，此时，Ｈ＿２脱附位基本上不受Ｈ＿２还原温度影响，主要显示了骨架ＳｉＯ＿２及ＴｉＯ＿２、Ｌａ＿２Ｏ＿３涂层氧化物对金属Ｐｄ起的作用。最后考察了甲醇分解反应，结果证实，改性Ｐｄ／ＴｉＯ＿２／ＳｉＯ＿２、Ｐｄ?更多还原

【Abstract】 Two wt. percent Palladiun1 were supported on pure supports（SiO₂、TiO₂、La₂O₃ and ZrO₂ ）and coated supports（TiO₂/SiO₂、 ZrO₂/SiO₂、 La₂O₃/SiO₂ ）. After reducing at473K（LTR） and 773K（HTR ） by hvdrogen,the samples were characterized by hydrogen-Oxygen titration,temperature programmed desorption（TPD）of hydrogen and methanol de-composition reaction.All the samples except Pd/SiO₂、Pd/ZrO₂ and Pd/ZrO₂/SiO₂ show de-pressed chemisorption of H₂ when treated at HTR , compared to the results of LTR. Thesamples Pd/TiO₂/SiO₂、Pd/La₂O₃/SiO₂ and Pd/ZrO₂ /SiO₂ have stronger H₂ chemisorptionthan samples prepared from pure supports（Pd/SiO₂ , Pd/TiO₂ , Pd/ZrO₂ and Pd/La₂O₃）, in-dicating that in the promoted catalysts , Pd is better dispersed. The order of SMSI detectedin these samples is at follows :Pd/TiO₂>Pd/La₂O₃>Pd/TiO₂/SiO₂>Pd/La₂O₃/SiO₂>Pd/SiO₂=pd/ZrO₂ = pd/ZrO₂/SiO₂. In TPR tests thereduction peaks of promoted Pd/SiO₂ sam-ples appeared at lower temperatures with higher intensity than in the case of pure Pd/SiO₂.Differences in TPD profiles between LTR and HTR samples agree well with differences in H₂-O₂ titration data, Compared to Pd on pure TiO₂ and La₂O₃ , the samples Pd/TiO₂/SiO₂ andPd/La₂O₃/SiO₂ are not sensitive to HTR with respect to H₂ chemisorption. At given reactionconditions,Pd/TiO₂ /SiO₂、Pd/La₂O₃/SiO₂ and Pd/ZrO₂/SiO₂ have high activity for methanoldecomposition and they are not affected by reduction temperature.更多还原