CAJ | 학술논문

以多羟基有机物α-或γ-环糊精为分散促进剂制备了Ni/SBA-15催化剂，通过N2吸附-脱附、X射线衍射、透射电镜、程序升温还原和热重等手段对该催化剂的物理化学性质进行了表征，并将其应用于甲烷二氧化碳重整(CRM)制合成气反应。结果显示，与采用传统浸渍法制备的Ni/SBA-15催化剂相比，采用α-或γ-环糊精改性法制备的催化剂具有更小的NiO颗粒，并在CRM中显示出更高的催化活性及更强的抗积碳性能。机理研究表明，采用传统浸渍法制备Ni/SBA-15催化剂时，浸渍液中的Ni2+主要在浓度梯度的作用下逐渐进入到SBA-15孔道内部， Ni2+水合物容易团聚，分散程度较低；而采用α-或γ-环糊精改性方法制备催化剂时，在水溶液中Ni2+与环糊精形成包覆物，环糊精携带Ni2+进入SBA-15孔道内，并且环糊精的存在使得Ni2+之间相互隔离，以高度分散形态存在于SBA-15孔道表面，有利于后续热处理中NiO在载体上较好地分散。
이다간기유궤물α-혹γ-배호정위분산촉진제제비료Ni/SBA-15최화제，통과N2흡부-탈부、X사선연사、투사전경、정서승온환원화열중등수단대해최화제적물이화학성질진행료표정，병장기응용우갑완이양화탄중정(CRM)제합성기반응。결과현시，여채용전통침지법제비적Ni/SBA-15최화제상비，채용α-혹γ-배호정개성법제비적최화제구유경소적NiO과립，병재CRM중현시출경고적최화활성급경강적항적탄성능。궤리연구표명，채용전통침지법제비Ni/SBA-15최화제시，침지액중적Ni2+주요재농도제도적작용하축점진입도SBA-15공도내부， Ni2+수합물용역단취，분산정도교저；이채용α-혹γ-배호정개성방법제비최화제시，재수용액중Ni2+여배호정형성포복물，배호정휴대Ni2+진입SBA-15공도내，병차배호정적존재사득Ni2+지간상호격리，이고도분산형태존재우SBA-15공도표면，유리우후속열처리중NiO재재체상교호지분산。
Organic compounds containing multiple hydroxyl groups, namely α‐cyclodextrin and γ‐cyclode‐xtrin, were used as additives for promoting Ni dispersion on supported Ni/SBA‐15 catalysts. Cata‐lysts prepared using modified and unmodified impregnation methods were characterized using N2 adsorption‐desorption isotherms, X‐ray diffraction, transmission electron microscopy, tempe‐rature‐programmed reduction, and thermogravimetric analysis, and their catalytic performance in the CO2 reforming of methane (CRM) to syngas was evaluated. The results show that compared with Ni/SBA‐15 prepared using a conventional impregnation method, the cyclodextrin‐modified cata‐lysts had smaller NiO particles. They also exhibited higher catalytic activity and had stronger ability to resist carbon deposition in the CRM. Mechanistic studies showed that for the unmodified cata‐lysts, Ni2+could migrate into the channels of SBA‐15 as a result of concentration differences, and the Ni species were sintered during the following thermal treatment processes, and could not be well dispersed. In contrast, various types of complex were formed between Ni(NO3)2 and the cyclodex‐trins, and this would be favorable for Ni2+being taken into the channels of the SBA‐15. The presence of cyclodextrins was beneficial to the mutual isolation of Ni species, and finally resulted in better dispersion of Ni species.