摘要
Anatase TiO_(2)nanospindles containing 89%exposed{101}facets(TIO_(2)-101)and nanosheets with 77%exposed{001}facets(TiO_(2)-001)were hydrothermally synthesized and used as supports for Pd catalysts.The effects of the TiO_(2)materials on the catalytic performance of Pd/TiO_(2)-101 and Pd/TiO_(2)-001 catalysts were investigated in the selective hydrogenation of acetylene to polymer-grade ethylene.The PdfTiO_(2)-101 catalyst exhibited enhanced performance in terms of acetylene conversion and ethylene yield.To understand these effects,the catalysts were characterized by H_(2)temperature-programmed desorption(H_(2)-TPD),H_(2)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 TiO_(2)-101 support had a smaller average particle size(1.53 nm)and a higher dispersion(15.95%)than those on the TiO_(2)-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/TiO_(2)-101 catalyst provided more reaction active sites,which contributed to the improved catalytic activity of this supported catalyst.
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。
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2017年第3期602-610,共9页
Acta Physico-Chimica Sinica
基金
国家自然科学基金(21476145)资助项目
