贵金属钯修饰的钴基介孔催化剂Pd-Co/SBA15的构效关系研究

Structure-performance Relationship on Palladium Promoted Co/SBA-15 Catalyst

制备了贵金属钯修饰的钴基介孔催化剂Pd-Co-SBA-15,采用低温液氮吸脱附、X射线粉末衍射、X射线光电子能谱、氢氧滴定和程序升温技术对其进行了表征,考察了钯助剂的加入量对钴基介孔催化剂结构和织构、表面性能及甲烷催化燃烧等方面性能的影响.结果表明,贵金属钯的加入可显著促进氧化钴物种的还原,有利于活性物种的表面富集,使催化剂上钴物种表面浓度由2.80Co/nm2增加到3.58Co/nm2,活性比表面积增加6.9m2/g.适量贵金属钯的加入可使样品在低温下迅速起活且T90%低于350℃;在整个稳定性考察过程中,双组分样品活性没有出现下降,且其甲烷转化率明显高出参比样85%.

Palladium promoted Co/SBA-15 Catalysts were prepared and characterized by N2 adsorption/desorption, X-ray diffraction, X-ray photoelectron spectroscopy, hydrogen-oxygen titration and temperature programming reduction techniques. Effects of palladium content on the properties and on the catalytic performance were investigated.The results indicated that the addition of palladium promoted the reduction and surface enrichment of cobalt oxide species obviously. The cobalt surface density was increased from 2.80 Co/nm^2 to 3.58 Co/nm^2 and the active surface area was aggrandized by 6.9 m^2/g. As a resuh, T90% values of the catalysts containing more than 0.7 % Pd were lower than 350℃, the CH4 conversion was 85% higher than that of the conventional sample during the whole activity test remarkably.