Preparation Of Boron Nitride Nanosheet Supported Pt/Cu Catalyst And The Study On Catalytic Performance Of Propane Dehydrogenation

Recently,the propane dehydrogenation to propylene becomes one of the most promising and attractive techniques because the greatly increasing demand for propylene and the success in the large-scale exploitation of shale gas.In this process,the platinum-based catalysts exhibit the most superior performance due to its unique activating ability for C-H bonds and environment friendly character.However,platinum is a scarce resource in nature,and its high price has inspired researchers to develop more effective methods to optimize the platinum utilization efficiency.At present,the commonly used methods include modifying catalysts,such as choosing suitable support materials and adding promoter,or preparing small-sized clusters or even single-atom catalysts to optimize the utilization of platinum.It also can be noted from the existing literature that a platinum loading of 0.1wt%almost is the reported lowest value that can keep considerable catalytic activity.In order to further reduce platinum usage while improving its catalytic activity,herein,we started from the selection of the active component precursor and the selection and modification of the support material,and then a high-efficiency and stable Pt-based catalyst for propane dehydrogenation with ultra-low loading was prepared.Subsequently,the catalytic activity was related to support structure,and the influence of the support structure on the dehydrogenation activity of the catalyst was analyzed at the same time.This will provide the experimental basis for other catalytic reactions involving platinum catalysts.The specific research contents of this paper are as follows:（1）The h-BN nanosheets（denoted as h-BN-sheet）were prepared by using the urea-assisted ball milling methods for commercially available h-BN.Meanwhile,Al₂O₃,SiO₂,SiC,HZSM-5 and h-BN-sheet materials were selected as carriers,0.1wt%Pt/Cu/support catalyst was prepared by impregnation method and then its propane dehydrogenation performance was tested.Because Pt/Cu/h-BN-sheet catalyst has better dispersion and more dehydrogenation sites are exposed,which makes the catalyst has better propane dehydrogenation performance than other supported Pt/Cu catalysts.（2）Pt/Cu/h-BN-sheet catalyst with ultra-low platinum usage was prepared by impregnation method and then its propane dehydrogenation performance was tested.Abundant fault edges of h-BN nanosheet and strong bonding interaction between copper and edge B-O defect maintain the unique geometry and elctronic state of Pt/Cu cluster.Consequently,only trace platinum（100 ppm）can obtain the considerable conversion（15%）of propane and high selectivity（99.8%）toward propylene at a relatively low reaction temperature（520?C）.Notably,such a catalyst showed a very high specific activity of propylene formation,⁷.3 mol _C3H6 mol^-_Pt¹ s^-1,greatly promoting the platinum utilization efficiency.