Kente Thobeka, Dube Sibongile M A, Coville Neil J, Mhlanga Sabelo D
Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag 3, Wits, 2050 Johannesburg, South Africa.
J Nanosci Nanotechnol. 2013 Jul;13(7):4990-5. doi: 10.1166/jnn.2013.7578.
This paper reports on the synthesis and use of nanostructures of gallium nitride (GaN NSs) and nitrogen doped carbon spheres (NCSs) as support materials for the hydrogenation of cinnamaldehyde. This study provides the first investigation of GaN as a catalyst support in hydrogenation reactions. The GaN NSs were synthesized via chemical vapour deposition (CVD) in a double stage furnace (750 degrees C) while NCSs were made by CVD in a single stage furnace (950 degrees C) respectively. TEM analysis revealed that the GaN NSs were rod-like with average diameters of 200 nm, while the NCSs were solid with smoother surfaces, and with diameters of 450 nm. Pd nanoparticles (1 and 3% loadings) were uniformly dispersed on acid functionalized GaN NSs and NCS. The Pd nanoparticles had average diameters that were influenced by the type of support material used. The GaN NSs and NCSs were tested for the selective hydrogenation of cinnamaldehyde in isopropanol at 40 and 60 degrees C under atmospheric pressure. A comparative study of the activity of the nanostructured materials revealed that the order of catalyst activity was 3% Pd/GaN > 3% Pd/NCSs > 1% Pd/NCSs > 1% Pd/GaN. However, 100% selectivity to hydrocinnamaldehyde (HCALD) was obtained with 1% Pd/GaN at reasonable conversion rates.
本文报道了氮化镓纳米结构（GaN NSs）和氮掺杂碳球（NCSs）的合成及其作为肉桂醛加氢反应载体材料的应用。本研究首次对GaN作为加氢反应中的催化剂载体进行了调查。GaN NSs通过化学气相沉积（CVD）在双级炉（750摄氏度）中合成，而NCSs分别通过CVD在单级炉（950摄氏度）中制备。透射电子显微镜（TEM）分析表明，GaN NSs呈棒状，平均直径为200纳米，而NCSs为实心，表面更光滑，直径为450纳米。钯纳米颗粒（负载量为1%和3%）均匀分散在酸功能化的GaN NSs和NCS上。钯纳米颗粒的平均直径受所用载体材料类型的影响。在40和60摄氏度、大气压下，对GaN NSs和NCSs进行了在异丙醇中肉桂醛选择性加氢的测试。对纳米结构材料活性的比较研究表明，催化剂活性顺序为3% Pd/GaN > 3% Pd/NCSs > 1% Pd/NCSs > 1% Pd/GaN。然而，1% Pd/GaN在合理的转化率下对氢化肉桂醛（HCALD）具有100%的选择性。
