CAJ | 학술논문

以NH4HCO3为造孔剂通过一步水热法成功合成了介孔型单晶NiAl2O4纳米棒,并考察了不同反应条件对NiAl2O4形貌的影响.实验结果表明反应时间、反应物浓度、NH4HCO3加入量对产物形貌具有关键作用.用透射电子显微镜(TEM),高分辨透射电子显微镜(HRTEM),扫描电子显微镜(SEM)和X射线衍射仪(XRD)对NiAl2O4纳米棒的形貌、结构和组成进行表征,并用氮气吸附-脱附法对其比表面积和孔径分布进行了研究.以介孔型NiAl2O4纳米棒为催化剂,在固定床反应器上对甲苯进行催化实验,结果表明当水炭摩尔比为1.0、反应温度为700℃时,400 min反应时间内甲苯平均转化率高达86.5%,并具有较好的反应稳定性.比较了直接沉淀法制备的纳米颗粒作为催化剂在甲苯氢化催化裂解中的催化性能.结果表明水热法制备的棒状NiAl2O4催化剂比不用水热制备的催化剂催化活性要好.初步探讨了介孔型NiAl2O4纳米棒的可能形成机理.
이NH4HCO3위조공제통과일보수열법성공합성료개공형단정NiAl2O4납미봉,병고찰료불동반응조건대NiAl2O4형모적영향.실험결과표명반응시간、반응물농도、NH4HCO3가입량대산물형모구유관건작용.용투사전자현미경(TEM),고분변투사전자현미경(HRTEM),소묘전자현미경(SEM)화X사선연사의(XRD)대NiAl2O4납미봉적형모、결구화조성진행표정,병용담기흡부-탈부법대기비표면적화공경분포진행료연구.이개공형NiAl2O4납미봉위최화제,재고정상반응기상대갑분진행최화실험,결과표명당수탄마이비위1.0、반응온도위700℃시,400 min반응시간내갑분평균전화솔고체86.5%,병구유교호적반응은정성.비교료직접침정법제비적납미과립작위최화제재갑분경화최화렬해중적최화성능.결과표명수열법제비적봉상NiAl2O4최화제비불용수열제비적최화제최화활성요호.초보탐토료개공형NiAl2O4납미봉적가능형성궤리.
Mesoporous single-crystalline NiAl2O4 nanorods were successfully synthesized by a one-step hydrothermal method using a pore-forming agent (NH4HCO3). A series of controlled experiments were also carried out to better understand the formation mechanism of NiAl2O4 nanorods. The experimental results indicate that the reaction time, reactant concentration and the amount of NH4HCO3 play an important role in determining the morphology. The morphology, structure and composition of the nanorods were investigated using transmission electron microscopy, high resolution transmission electron microscopy, scanning electron microscopy and X-ray diffraction. The specific surface area and pore-size distribution of the obtained product was determined by nitrogen adsorption-desorption measurements. NiAl2O4 nanorods have a high Brunauer-Emmett-Teller surface area and good porosity properties. The catalytic performance of the NiAl2O4 nanorods during toluene hydrocracking was investigated using a fixed bed reactor. After the toluene catalytic reactions over 400 min at a water stream/carbon molar ratio (H2O/C) of 1.0 with a reaction temperature of 700 ℃ the average conversion efficiency of toluene was about 86.5%. Compared to the NiAl2O4 nanoparticles prepared by alkaline precipitation, the mesoporous NiAl2O4 nanorods exhibited higher catalytic activity and stability during toluene hydrocracking. A possible formation mechanism for the mesoporous NiAl2O4 nanorods is proposed and discussed.