The Preparation Of MOF-derived Carbon-based Material Supported Ruthenium Catalyst And Its Catalytic Hydrogen Production Performance

Hydrogen energy is seen as the most promising clean energy to contribute to sustainable development for human,and has been commercialized in hydrogen fuel cells.Ammonia with a high hydrogen storage density,is easy to be liquefied.Liquid ammonia is used as an ideal material for hydrogen storage.At the same time,the decomposition of ammonia to produce pure hydrogen has no carbon compounds,so is an ideal hydrogen supply carrier for hydrogen fuel cells.The heat treated derivative carbon-based materials of MOF materials have received extensive attention in many fields due to their good electronic conductivity,controllable pore structure,and their good thermal stability.However,there are few reports in the field of hydrogen catalytic production by ammonia decomposition based on MOF thermal decomposition.Therefore,in this paper,a series of Ru-based catalysts are prepared by using MOF derived carbon-based materials as catalytic carriers,and XRD,TEM,Raman,and the adsorption and desorption of N2 are adopted.The characterization techniques such as H2-TPR and the fixed bed catalytic performance test study the correlation between the catalyst structure and ammonia decomposition catalytic activity.The main contents include the following parts:(1)The study of Ru-based catalyst based on the UiO-66 series derivative carbon-based carrier material and its catalytic hydrogen production performance.Under the hydrothermal method,UiO-66 and UiO-66-NH2 were successfully synthesized,and then heated in an argon atmosphere to obtain four carrier materials:ZrO2/CN,ZrO2/C,CN,and C.This is used as a carrier to load Ru for ammonia decomposition to produce hydrogen.The results show that the reduction order of the catalytic activity of ammonia decomposition is Ru-ZrO2/CN>Ru-ZrO2/C>Ru-CN>Ru-C under the conditions of 500?and 6000 h-1.Among them,2%Ru-ZrO2/CN catalyst has a minimum activation energy of 31.60 kJ/mol.After 3000 min stability test,the catalyst still has high catalytic activity.(2)The study of Ru-Co biinetallic catalyst based on ZIF series derived carbon-based carrier materials and its catalytic hydrogen production performance.Using the normal room temperature static method,ZIF-8,ZIF-67,and ZIF-67@ZIF-8(x)are synthesized,and then these metal organic frame precursors are heat treated to obtain DC,respectively.Co/CN and CS-Co/CN(x)porous carbon and nitrogen materials are loaded on composite porous carbon materials by equivalent volume impregnation.The catalytic performance test results show that under the conditions of 500? and 6000 h-1,Ru-CS-Co/CN(l)(92.61%)>Ru-CS-Co/CN(0.5)(89.84%)>Ru-CS-Co/CN(2)(73.23%)>Ru-Co/CN(55.2%).According to Arrhenius equatioin,activation energy of catalysts was 48.40 kJ/mol,45.91 kJ/mol,50.32 kJ/mol and 71.07 kJ/mol,respectively.After 3000 min reaction,the catalytic activity of Ru-CS-Co/CN(l)was still unchanged,exhibiting a very good catalytic stability.(3)Preparation of Ru-based catalysts by special field plasma strengthening and its catalytic hydrogen production performance.Select 2%Ru-ZrO2/CN and Ru-CS-Co/CN(l)as precursors,discharge frequency at 15 kHz,continuous treatment for 30 minutes,and then high temperature reduction,Ru-ZrO2/CN-P and Ru-CS-Co/CN-P catalysts were obtained respectively.The experimental results show that plasma treatment can reduce the particle size of metal particles to a certain extent,increase the dispersion of active components and enhance the metal-carrier interaction.The ammonia decomposition activity at 550? of the conventionally prepared Ru-CS-Co/CN catalyst was 92.61%,and the plasma-treated Ru-CS-Co/CN-P ammonia decomposition activity increased by 3.81%.However,comparing to Ru-ZrO2 catalyst,Ru-ZrO2/CN-P did not significantly increase its activity under the same treatment conditions.