中文摘要：

采用水热法合成了含有89%{101}晶面的TiO_2纳米锭（TiO_2-101）和77%{001}晶面的TiO_2纳米片（TiO_2-001）,将其用作载体来制备担载钯催化剂;研究了上述制备的TiO_2纳米材料对Pd/TiO_2-101和Pd/TiO_2-001催化剂用于乙炔选择加氢制聚合级乙烯催化性能的影响。结果表明,Pd/TiO_2-101催化剂表现出更好的乙炔转化率和乙烯收率。通过氢气程序升温脱附（H_2-TPD）、氢气程序升温还原（H_2-TPR）、透射电子显微镜（TEM）、CO化学吸附、X射线光电子能谱（XPS）和热重分析仪（TGA）等对催化剂进行了结构表征和分析。TEM和CO化学吸附结果表明,Pd纳米颗粒（NPs）在TiO_2-101载体上有较小的颗粒尺寸（1.53 nm）和较高的分散度（15.95%）;而Pd纳米颗粒在TiO_2-001载体上的颗粒尺寸是4.36 nm和9.06%的分散度。Pd/TiO_2-101催化剂上较小的Pd颗粒尺寸及其较高的分散度使催化剂具有更多的反应活性位点,这促进了其反应的催化活性。

英文摘要：

Anatase TiO2 nanospindles containing 89% exposed {101} facets （TIO2-101） and nanosheets with 77% exposed {001} facets （TiO2-001） were hydrothermally synthesized and used as supports for Pd catalysts. The effects of the TiO2 materials on the catalytic performance of Pd/TiO2-101 and Pd/TiO2-001 catalysts were investigated in the selective hydrogenation of acetylene to polymer-grade ethylene. The PdfTiO2-101 catalyst exhibited enhanced performance in terms of acetylene conversion and ethylene yield. To understand these effects, the catalysts were characterized by H2 temperature-programmed desorption （H2-TPD）, H2 temperature- programmed reduction （H=-TPR）, transmission electron microscopy （TEM）, pulse CO chemisorption, X-ray photoelectron spectroscopy （XPS）, and thermogravimetric analysis （TGA）. The TEM and CO chemisorption results confirmed that Pd nanoparticles （NPs） on the TiO2-101 support had a smaller average particle size （1.53 nm） and a higher dispersion （15.95%） than those on the TiO2-001 support （average particle size of 4.36 nm and dispersion of 9.06%）. The smaller particle size and higher dispersion of Pd on the Pd/TiO2-101 catalyst provided more reaction active sites, which contributed to the improved catalytic activity of this supported catalyst.