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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
  • ISSN号:1000-6818
  • 期刊名称:《物理化学学报》
  • 时间:0
  • 分类:O643[理学—物理化学;理学—化学]
  • 作者机构:厦门大学化学化工学院、固体表面物理化学国家重点实验室、醇醚酯化工清洁生产国家工程实验室,福建厦门361005
  • 相关基金: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
中文摘要:

以乙酰丙酮铑(Rh(acac)3)和乙酰丙酮钐(Sm(acac)3)为前驱体,用浸渍法制备了Rh/SiO2和Rh-Sm2O3/SiO2催化剂。采用原位红外光谱、热重分析、低温N2吸附、X射线粉末衍射、高分辨透射电子显微镜、H2-程序升温还原和X射线光电子能谱等实验技术对催化剂的制备过程,比表面积和物相以及Rh与Sm2O3间的相互作用进行了表征,并以甲烷部分氧化制合成气为目标反应对催化剂的稳定性进行了考察。研究表明:以Rh(acac)3和Sm(acac)3为前驱体采用简单的浸渍法即可制备出Rh平均粒径为2.3 nm且具有良好抗烧结性能的Rh-Sm2O3/SiO2催化剂。在浸渍过程中乙酰丙酮化合物通过与SiO2表面羟基形成氢键而负载于载体表面。Sm(acac)3在SiO2表面的单层负载量(质量分数)约为31%,对应于Sm2O3的质量分数约为15%,只要Sm(acac)3的质量分数低于这一阈值,均可保证分解后生成的Sm2O3以高分散形式负载于SiO2上,且不会因高温(800℃)焙烧而团聚。高分散于SiO2表面的Sm2O3与Rh之间存在强的相互作用,可显著提高Rh的分散度,防止其在高温反应条件下烧结,进而使低Rh负载量的催化剂表现出良好的甲烷部分氧化制合成气反应活性和稳定性。

英文摘要:

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 hi

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期刊信息
  • 《物理化学学报》
  • 中国科技核心期刊
  • 主管单位:中国科学技术协会
  • 主办单位:北京大学化学与分子工程学院承办
  • 主编:刘忠范
  • 地址:北京大学化学楼
  • 邮编:100871
  • 邮箱:whxb@pku.edu.cn
  • 电话:010-62751724
  • 国际标准刊号:ISSN:1000-6818
  • 国内统一刊号:ISSN:11-1892/O6
  • 邮发代号:82-163
  • 获奖情况:
  • 中文核心期刊
  • 国内外数据库收录:
  • 俄罗斯文摘杂志,美国化学文摘(网络版),荷兰文摘与引文数据库,美国科学引文索引(扩展库),英国科学文摘数据库,日本日本科学技术振兴机构数据库,中国中国科技核心期刊,中国北大核心期刊(2004版),中国北大核心期刊(2008版),中国北大核心期刊(2011版),中国北大核心期刊(2014版),英国英国皇家化学学会文摘,中国北大核心期刊(2000版)
  • 被引量:24781