La助剂对Pd/γ-Al2O3催化C3H8氧化性能的影响  

Influence of La Promoter in Pd/Al2O3 Catalyst on C3H8 Oxidation

作　　者：陈超[1,2] 王成雄 姚丽鹏[1,2] 郑婷婷 赵云昆 Chen Chao;Wang Chengxiong;Yao Lipeng;Zheng Tingting;Zhao Yunkun(State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals, Kunming Institute of Precious Metals, Kunming 650106,China;State-Local Joint Engineering Laboratory of Precious Metal Catalytic Technology and Application, Kunming Sino-Platinum Metals Catalyst Co. Ltd, Kunming 650106,China)

机构地区：[1]昆明贵金属研究所稀贵金属综合利用新技术国家重点实验室,云南昆明650106 [2]昆明贵研催化剂有限责任公司贵金属催化技术与应用国家地方联合工程实验室,云南昆明650106

出　　处：《稀有金属材料与工程》2019年第6期2027-2032,共6页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(21463015);云南省应用基础研究计划项目(2014FA045,2016FD123)

摘　　要：采用不同稀土La前驱体浸渍掺杂改性Pd/γ-Al2O3催化剂,利用多功能催化性能评价装置测试不同催化剂对C3H8的催化氧化性能,并通过H2-TPR、XRD、XPS等对催化材料进行结构表征。结果表明:La能促进贵金属钯分散,增强钯与载体相互作用,稳定高活性Pd^2+物种,从而提高了催化剂对C3H8的催化氧化性能。在选用不同La前驱体改性的Pd/γ-Al2O3催化剂中,硝酸镧改性效果最佳,能更好地促进活性金属钯的分散和Pd^2+高活性物种的稳定。相比Pd/γ-Al2O3,La改性催化剂均降低了C3H8和NO的反应转化温度。选用不同La前驱体对催化活性影响存在差异的主要原因是La前驱体添加而引起的金属-载体相互作用和活性贵金属钯的分散状态变化。Different rare earth La precursors were used to modify Pd/γ-Al2O3 catalyst via an incipient wetness impregnation method.C3H8oxidation performance was studied using a powder sample evaluation device and the structures of catalysts were characterized through H2-TPR,XRD,XPS,etc.The results show that addition of lanthanum effectively promotes palladium dispersion,strengthens Pd-support interaction and stabilizes highly-active Pd^2+species,thus improving the catalytic activity for C3H8 oxidation.Addition of lanthanum nitrate shows the best promoting-effect in palladium dispersion and stabilization of highly-active Pd^2+species.Compared with Pd/γ-Al2O3,La-modified catalysts show lower Ts,T50 and T90 values for C3H8 and NO conversion.Lanthanum addition induces changes in metal-support interaction and dispersive state of active species,which plays a significant role in enhancing activity for C3H8 catalytic oxidation.

关 键 词：LA 钯催化剂 金属-载体相互作用 C3H8氧化 

分 类 号：O643.36[理学—物理化学] TQ138.23[理学—化学]