配体调控负载Pd催化剂苯乙炔半加氢性能研究

Ligand Regulation Supported Pd Catalyst Properties of Semi-hydrogenation of Phenylacetylene

文章采用3-氨丙基三乙氧基硅与正硅酸酯为原料,通过溶胶-凝胶法合成氨丙基改性氧化硅载体,氨丙基进一步与甲醛反应制得新有机基团改性硅载体(CH2O-SiO2)。采用CH2O-SiO2为载体合成负载Pd催化剂(Pd/SiO2-N)。对比研究采用商业氧化硅负载Pd催化剂(Pd/C-SiO2)和Pd/SiO2-N催化剂苯乙炔性能,结果表明,对于苯乙炔加氢,在这两种催化剂上,苯乙烯选择性均随苯乙炔转化率的增加而降低,但是在Pd/C-SiO2催化剂上获得较高苯乙烯选择性。FTIR和TEM表征结果表明,Pd/SiO2-N上Pd粒径比Pd/C-SiO2催化剂上Pd粒径较小,这可能是实验结果差异的原因。

Aminopropyl-functionalized silica （NH2-SiO2） was obtained via a sol-gel process using tetraethoxylsilicate （TEOS） and aminopropyltriethoxysilane （APTES）. Aminopropyl group contained silica was further modified with formaldehyde to achieve novel organic group modified silica, denoted as CH20-SiO2. Using CH20-SiO2 as surport to prepare surported Pd catalyst （denoted as Pd/M-SiO2）, small Pd nanoparticles （1-2 rim） were fabricated on CH20-SiO2 surport. Semihydrogenation of phenylacetylene was carried out over Pd supported on a commercial SiO2 support（Pd/C-SiO2） and Pd/M-SiO2 catalyst. The results indicated that styrene selectivity decreased with the increase of phenylacetylene conversion, and higher styrene selectivity was obtained over Pd/C-SiO2. The result of TEM indicated smaller Pd patticles was obtained for Pd/M-SiO2 catalyst compared with that of Pd/C-SiO2catalyst.