Preparation Of Iron-based Nanotube Catalyst And Evaluation Of Hydrogenation Performance In The Process Of Direct Coal Liquefaction

Coal resources has been one of the most important energy in our country,along with the adjustment of energy structure and the requirement for environmental protection,the clean coal utilization become more and more important,and transformation the mode of the use of coal resources become necessary,direct coal liquefaction technology provides an efficient way for clean coal utilization,in the related study of direct coal liquefaction,the synthesis and preparation of catalyst used in direct coal liquefaction has occupied a very important position and it also determined the efficient utilization of coal resources,at present,iron based nanoparticles catalyst has become the priority choice and the application research of catalysts with special morphology in direct coal liquefaction process is relatively small,therefore,nanotubes materials was chose as the research object which has relatively high specific surface area and pore structure of one dimensional,trying to synthesis and study its property.In this subject,we choose soft template method to synthesis the nanotube material.Firstly,the effect of the influence factors on the morphological characteristics of the synthesized iron oxide products was investigated by using sodium lauryl sulfate(SDS)as the template.We studied the concentration of surfactant,the type of precipitant,the type of ferric salt and their influence on the morphological characteristics of the synthesized iron oxide products in the reaction process.The experiment result shows that in the related synthesis experiments with SDS as a soft template.The type of precipitant had a great influence on the morphology of the products,there are significant differences in the morphology of the samples under different precipitant conditions.Ellipsoidal nanoparticles with relatively uniform appearance was obtained when use Na2CO3 as precipitant.When ammonia was used as precipitant,some tubular products appeared but the yield was low.Related research also found that the same reaction conditions there are large difference between the product obtained under the condition of use different ferric salt,this may be due to the change of ion composition in the reaction system may affects the morphology of micelles.On the basis of the conclusion obtained in the above experiment,we use SDBS as a template to further study the synthesis condition of iron oxide nanotubes.The influence of the type of precipitant was studied in the first,in the study we found that when NaOH was used as precipitant,it could obtain the relatively regular nanotube materials.In the further synthesis study,we using the SDBS as the template and NaOH as the precipitant optimized the synthesis experiments.The influence of the concentration conditions of SDBS and iron salts on the morphological characteristics of the nanotubes was investigated.It was found that when the added amount of SDBS in the reaction was 1.4mmol,the morphological characteristics of the nanotube is relatively superior,when the additive amount of the ferric salt rise to more than 1g,we can obtained Fe2O3 nanotube with the tube diameter about 200nm and the length about 300nm.When the addition of iron salt was lower than 0.8g,a longer rod structure appeared in the product.The TEM characterization shows that it is a hollow nanotube tubular structure with the tube diameter about 100nm and the length about 500-700nm.When the amount of iron salt is reduced to 0.5g.In the product,the tube length can reach 1?m,and the tube diameter is 80-100nm.Finally,we used the lignite from Hei Longjiang province as the research object to study the hydrogenation performance of the catalyst synthesis in the experiment process with different nanometer morphology and corresponding evaluation was given when compared study was done on the catalytic performance of commercial Fe2O3.