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提出了一种无需涂层就可获得较高Pd负载量,且分散性好的Pd/堇青石催化剂的制备方法。对堇青石载体及孔道表面进行氨基官能团化,然后负载金属Pd。利用傅里叶红外光谱(FT-IR)、X射线衍射(XRD)、透射电镜(TEM)、电感耦合等离子体发射光谱(ICP-AES)以及滴定方法表征载体表面及负载的Pd粒子。结果表明,在3-氨丙基三乙氧基硅烷(APTS)与载体质量比0.015、80℃条件下对堇青石改性12h,所得载体负载金属Pd,可得到最高的Pd粒子分散度,制备的Pd/堇青石催化剂表现出对苯乙烯加氢反应最高的活性。采用N-氨乙基-γ-氨丙基三甲氧基硅烷(TPED)改性堇青石载体,Pd粒子负载量能提高1倍以上,但Pd粒子的分散度降低。此外堇青石的酸预处理不利于其氨基官能团化和Pd粒子在其上的分散。
A method for preparing Pd / cordierite catalyst with higher Pd loading and good dispersibility without coating was proposed. Amino functionalization of the cordierite support and pore surface followed by loading of metal Pd. The surface and supported Pd particles were characterized by FT-IR, XRD, TEM, ICP-AES and titration methods. The results showed that the cordierite was modified with 3-aminopropyltriethoxysilane (APTS) and carrier at a mass ratio of 0.015 and 80 ℃ for 12h, and the highest Pd particle dispersion Pd / cordierite catalyst exhibited the highest activity for the hydrogenation of styrene. With the cordierite carrier modified with N-aminoethyl-γ-aminopropyltrimethoxysilane (TPED), the loading of Pd particles can be more than doubled, but the dispersibility of Pd particles decreases. In addition, acid pretreatment of cordierite is detrimental to its amino functionalization and dispersion of Pd particles thereon.