保护剂对Au-Pd/CeO_2催化剂甲醇部分氧化性能的影响

以聚乙烯吡咯烷酮(PVP),聚乙烯醇(PVA)和聚乙二醇(PEG4000)为保护剂分别制备了Au-Pd/CeO2催化剂,考察了不同保护剂对甲醇部分氧化性能的影响,并运用XRD、TPD和TPR等手段对催化剂进行了表征。结果表明,与以PVA或PEG为保护剂制备的Au-Pd/CeO2催化剂相比,以PVP为保护剂制备的Au-Pd/CeO2催化剂中Au沉积率较高,形成的AuxPdy合金较多,金属与载体的相互作用较强,对甲醇吸附量较小,载体表面Ce3+的含量较高,CeO2晶格氧向表面迁移较容易,这使得以PVP为保护剂制备的Au-Pd/CeO2催化剂有较好的甲醇部分氧化反应活性。

Effects of Protectants on Properties of Au-Pd/CeO2 Catalysts for the Partial Oxidation of Methanol

Several polyelectrolyte-stabilized Au-Pd/CeO2 catalysts were prepared using polyvinylpyrrolidone(PVP),poly(vinyl alcohol)(PVA) or polyethylene glycol(PEG 4000) as protectants and their catalytic performance for partial oxidation of methanol were studied.XRD,TPR and TPD were used to characterize the catalysts.It was found that gold deposited better and had much more AuxPdy alloy in the AuPd/CeO2 catalyst prepared using PVP as protectant,and compared with the Au-Pd/CeO2 catalysts prepared using PEG or PVA as protectant,the former had stronger interaction between Au-Pd and support,lower methanol adsorption,and formed more Ce3+on the surface of CeO2 support,while the crystal lattice oxygen of CeO2 migrated to the surface more easily,all these made the catalyst using PVP as protectant had better catalytic activity.