Hydrodeoxygenation of dibenzofuran over SiO2, Al2O3/SiO2 and ZrO2/SiO2 supported Pt catalysts
Hydrodeoxygenation of dibenzofuran over SiO2, Al2O3/SiO2 and ZrO2/SiO2 supported Pt catalysts
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DOI：
10.1039/c4cy00859f
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发表时间：
2015
影响因子：
5
通讯作者：
Lei Wang;Huihui Wan;Shaohua Jin;Xiao Chen;Chuang Li;Changhai Liang
中科院分区：
文献类型：
--
作者：
Lei Wang;Huihui Wan;Shaohua Jin;Xiao Chen;Chuang Li;Changhai Liang
通过沉积高度分散的Al 2 O3或ZrO 2氧化物，对具有介孔（SiO2）的二氧化硅表面进行后改性。负载的Pt改性的二氧化硅载体上产生更高的金属分散相对于母体二氧化硅的基础上的CO化学吸附和透射电子显微镜的结果。二苯并呋喃（DBF）在Pt催化剂上的加氢脱氧（HDO）反应主要是通过芳环加氢和C-O键断裂生成无氧烃类。在较小的Pt纳米颗粒上观察到芳环的可氢化氢化。NH3-TPD结果表明，Al 2 O3/SiO2或ZrO 2/SiO2催化剂具有较强的酸性，促进了六氢二苯并呋喃的选择性C-O键断裂，从而改变了HDO反应途径.负载在Al 2 O3或ZrO 2改性的二氧化硅载体上的小尺寸Pt纳米颗粒显示出上级HDO性能，与未改性的二氧化硅相比具有增强的脱氧能力。根据准一级动力学分析，在恒温条件下，HDO反应速率常数的大小顺序为：Pt/Al 2 O3/SiO2 > Pt/ZrO 2/SiO2 > Pt/SiO2，这是由于分散的金属颗粒和载体酸性中心的协同作用。
The surface of silica with mesopores (SiO2) was post-modified by the deposition of highly dispersed Al2O3 or ZrO2 oxides. Loading of Pt on the modified silica supports yielded higher metal dispersion with respect to the parent silica based on the CO chemisorption and transmission electron microscopy results. Hydrodeoxygenation (HDO) of dibenzofuran (DBF) over the as-prepared Pt catalysts mainly proceeds via the hydrogenation of the aromatic rings, which is followed by the cleavage of the C–O bond to produce oxygen-free hydrocarbons. Preferable hydrogenation of the aromatic rings is observed over the smaller Pt nanoparticles. The relatively strong acidic properties of Al2O3/SiO2 or ZrO2/SiO2, revealed by the NH3-TPD profiles, promote the selective C–O bond cleavage of hexahydrodibenzofuran to alter the HDO reaction pathway. The small sized Pt nanoparticles supported on the Al2O3 or ZrO2 modified silica supports show superior HDO performance with enhanced deoxygenation ability to those over unmodified silica. According to the pseudo-first-order kinetics analysis, the fitted HDO rate constant follows the order: Pt/Al2O3/SiO2 > Pt/ZrO2/SiO2 > Pt/SiO2 under a constant temperature, which is attributed to the cooperative function of the dispersed metal particles and the acidic sites of supports.