物理化学学报2017，Vol.33Issue(8)：1689-1698,10.DOI:10.3866/PKU.WHXB201704243
抗烧结Rh-Sm2O3/SiO2催化剂的制备和表征及其甲烷部分氧化制合成气性能
Preparation and Characterization of Sinter-Resistant Rh-Sm2O3/SiO2 Catalyst and Its Performance for Partial Oxidation of Methane to Syngas
摘要
Abstract
Rh/SiO2 and Rh-Sm2O3/SiO2 catalysts were synthesized by the conventional impregnation method using rhodium acetylacetonate (Rh(acac)3) and samarium acetylacetonate (Sm(acac)3) as precursors.The preparation and catalytic properties,as well as the interaction between Rh and Sm2O3,were characterized in detail by in situ infrared spectroscopy (IR),thermogravimetric analysis (TG),N2 physisorption (Brunauer-Emmett-Teller (BET) method),X-ray powder diffraction (XRD),transmission electron microscopy (TEM),temperature-programmed reduction (H2-TPR) and X-ray photoelectron spectroscopy (XPS).The performance of the catalysts for the partial oxidation of methane (POM) to syngas was also investigated.The results showed that a sinter-resistant Rh-Sm2O3/SiO2 catalyst with an average Rh particle size of ～2.3 nm could be synthesized using the conventional impregnation method with Rh(acac)3 and Sm(acac)3 as precursors.The surface silanol groups of SiO2 acted as the centers to interact with M(acac)3 (M=Rh,Sm) molecules when SiO2 was impregnated in the M(acac)3 solution,leading to the formation of a hydrogen-bonded M(acac)3 layer on the SiO2 surface.In this experiment,the monolayer coverage of Sm(acac)3 on the SiO2 surface was equal to a Sm(acac)3 loading (mass fraction) of approximately 31％,which in turn corresponded to a Sm2O3 loading of approximately 15％.When a Sm(acac)3/SiO2 sample with Sm(acac)3 loading below 31％ was heated in air to approximately 360 ℃,the monolayer Sm(acac)3 species decomposed into highly dispersed Sm2O3 species on the SiO2 surface,which displayed superior stability against sintering at high temperature.No aggregation of the Sm2O3 species was observed even when the sample was heated to 800 ℃ in air.The strong interaction between the highly dispersed Sm2O3 and Rh plays a key role in increasing the dispersion of Rh species in the catalyst and preventing the Rh species from sintering under high temperature conditions.This factor should also be responsible for the superior activity and stability of the Rh-Sm2O3/SiO2 catalyst with extremely low Rh loading for the catalytic partial oxidation of methane to syngas.关键词
Rh-Sm2O3/SiO2/乙酰丙酮铑/乙酰丙酮钐/抗烧结/甲烷部分氧化/合成气Key words
Rh-Sm2O3/SiO2/Rh(acac)3/Sm(acac)3/Sinter-resistant/Partial oxidation of methane/Syngas分类
化学化工引用本文复制引用
郑芳芳,李倩,张宏,翁维正,伊晓东,郑燕萍,黄传敬,万惠霖..抗烧结Rh-Sm2O3/SiO2催化剂的制备和表征及其甲烷部分氧化制合成气性能[J].物理化学学报,2017,33(8):1689-1698,10.基金项目
The project was supported by the National Key Basic Research Program of China (2013CB933102),National Natural Science Foundation of China (21473144,21373168),National Talent Development of Basic Research Program of China (J1310024) and Program for Innovative Research Team in University,China (IRT_14R31).国家重点基础研究发展规划项目(2013CB933102),国家自然科学基金(21473144,21373168),国家基础科学人才培养基金项目(J1310024)及教育部创新研究团队项目(IRT_14R31)资助 （2013CB933102）
