W量对Pt_GaWZrO_...构及甘油选择氢解性能的影响_姜兰.pdf

研究论文 Article *E-mail:;;Tel.:021-31244679 Received December 26,2022;published February 17,2023.Supporting information for this article is available free of charge via the Internet at http:/sioc-.Project supported by the National Natural Science Foundation of China(No.22272030),State Key Laboratory of Catalytic Materials and Reaction En-gineering(RIPP,SINOPEC),and Science and Technology Commission of Shanghai Municipality(No.19DZ2270100).项目受国家自然科学基金(No.22272030)、石油化工催化材料与反应工程国家重点实验室(中国石油化工股份有限公司石油化工科学研究院)开放基金及上海市科委科技基金(No.19DZ2270100)资助.Acta Chim.Sinica 2023,81,231238 2023 Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences http:/sioc- 231 化 学 学 报 化 学 学 报 ACTA CHIMICA SINICA W 量对 Pt/GaWZrOx催化剂结构及甘油选择氢解性能的影响 姜兰a 范义秋a 张晓昕b 裴燕a 闫世润a 乔明华*,a 范康年a 宗保宁*,b(a复旦大学化学系 上海市分子催化和功能材料重点实验室 上海 200438)(b中国石化石油化工科学研究院 催化材料与反应工程国家重点实验室 北京 100083)摘要摘要 在甘油选择氢解制 1,3-丙二醇(1,3-PDO)反应中,Pt-WOx催化剂体系因其高活性和高选择性而受到研究者的广泛关注.本工作制备了 W 量不同的 Ga 掺杂 GaWZrOx固体酸(GaWZ),然后作为载体采用浸渍法制备了 Pt/GaWZ 催化剂,系统考察了 W 的量对催化剂物化性质和催化性能的影响.CO 化学吸附和 X 射线光电子能谱(XPS)表征发现,随着GaWZ载体中W量的增加,其上负载的Pt的分散度先增加,在10%(w)W的Pt/GaWZ(10)催化剂上达到最高值86%,然后在 15%(w)W 时降低.紫外-可见漫反射(UV-Vis DRS)、傅里叶变换红外(FTIR)和 XPS 表征表明,Pt/GaWZ 催化剂中的 W 与四方相 ZrO2表面的 ZrOH 基团存在较强作用,形成了单分散的 WOx物种;当大于 7.5%(w)W 时,开始出现第二层WOx物种.单分散的WOx物种可能是Pt分散度提高的重要原因.由程序升温氨脱附(NH3-TPD)和吡啶吸附红外(Py-IR)表征结果可见,W 的量越高,催化剂的酸量越大,Brnsted 酸和 Lewis 酸同时增加.在甘油氢解反应中,随着 W的增加,Pt/GaWZ 催化剂上的甘油转化率呈火山型变化趋势,而目标产物 1,3-PDO 的选择性则持续提高.1,3-PDO 得率在 Pt/GaWZ(10)催化剂上达到最高,为 47.5%,而且该催化剂有良好的套用稳定性.根据表征结果,我们推测 Pt 的分散度及 Pt 与 WOx物种之间的协同作用决定了 Pt/GaWZ 催化剂在甘油氢解反应中的活性;而 1,3-PDO 选择性与 Brnsted酸量之间呈现的良好的线性关系,说明 WOx物种上的 Brnsted 酸位是决定 Pt/GaWZ 催化剂上 1,3-PDO 选择性的关键.关键词关键词 钨含量;甘油氢解;1,3-丙二醇;铂分散度;Brnsted 酸 Effect of W Content on Structure and Catalytic Performance of Pt/GaWZrO of W Content on Structure and Catalytic Performance of Pt/GaWZrOx x Catalysts in Glycerol Selective Hydrogenolysis Catalysts in Glycerol Selective Hydrogenolysis Jiang,Lana Fan,Yiqiua Zhang,Xiaoxinb Pei,Yana Yan,Shiruna Qiao,Minghua*,a Fan,Kangniana Zong,Baoning*,b(a Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials,Department of Chemistry,Fudan University,Shanghai 200438,China)(b State Key Laboratory of Catalytic Materials and Reaction Engineering,Research Institute of Petroleum Processing,SINOPEC,Beijing 100083,China)Abstract The Pt-WOx catalyst system has received much attention for its high activity and selectivity in glycerol hydro-genolysis to 1,3-propanediol(1,3-PDO).In this work,the Ga-doped GaWZrOx solid acid supports(GaWZ)with different W contents were prepared,and then Pt/GaWZ catalysts were prepared by the wetness impregnation method.The effects of the W contents on the physicochemical properties and catalytic performance of the Pt/GaWZ catalysts were systematically inves-tigated.CO chemisorption and X-ray photoelectron spectroscopy(XPS)characterizations revealed that the dispersion of Pt on the GaWZ supports first increasesd with the increase in the W content,reached a maximum of 86%on the Pt/GaWZ(10)catalyst with 10%(w)of W,and then decreased at 15%(w)of W.UV-Vis diffuse reflectance(UV-Vis DRS),Fourier trans-form infrared(FTIR),and XPS characterization showed that the W in the Pt/GaWZ catalysts interacted with the ZrOH functional groups on the tetragonal phase ZrO2,thus forming mono-dispersed WOx species.When the W content was greater than 7.5%(w),the second layer of the WOx species began to emerge.The mono-dispersed WOx species may be conducive to the high dispersion of Pt.The results of the temperature-programmed desorption of NH3(NH3-TPD)and pyridine adsorption infrared(Py-IR)characterizations showed that the higher the W content,the higher the amount of the acid on the catalyst,with the simultaneous increase in the amounts of both the Brnsted acids and Lewis acids.In glycerol hydrogenolysis over the Pt/GaWZ catalysts,with the increase in the W content,the glycerol conversion evolved in a volcano-shaped trend,while DOI:10.6023/A22120509 化化 学学 学学 报报 研究论文 232 http:/sioc- 2023 Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences Acta Chim.Sinica 2023,81,231238 the selectivity to the target product 1,3-PDO increased monotonically.The highest yield of 1,3-PDO of 47.5%was achieved over the Pt/GaWZ(10)catalyst,and the catalyst also displayed excellent recycling stability.On the basis of the characteriza-tion results,we propose that the Pt dispersion and the synergistic interaction between Pt and WOx species determine the activ-ity of the Pt/GaWZ catalysts in glycerol hydrogenolysis,and the Brnsted acid site pertaining to the WOx species is the key to determine the selectivity to 1,3-PDO over the Pt/GaWZ catalysts,as evidenced by the good linear relationship between the 1,3-PDO selectivity and the amount of the Brnsted acid sites.Keywords W content;glycerol hydrogenolysis;1,3-propanediol;Pt dispersion;Brnsted acid 1 引言 生物柴油主要通过植物或动物油脂与甲醇、乙醇进行酯交换得到,故同时副产甘油1.由于生物柴油产业的蓬勃发展,预计 2025 年前世界粗甘油产量将超过四百万吨2,因此将其转化为高值化学品能够进一步提升生物柴油产业的经济效益.甘油作为十二大生物质平台分子之一,可以通过氧化途径转化为丙烯