Preparation And Catalytic Performances Of Porous Boron Nitride Microtubes

In the past few decades,the industrial demand for ethylene and propylene has been increasing.The current industrial method for producing low-chain olefins is mainly steam cracking in the petroleum industry,which often requires high temperature and high pressure and consumes a large amount of energy.In order to solve this problem,the oxidative dehydrogenation of alkanes has become a research hotspot,and a suitable catalyst is essential for this reaction.At the same time,with the continuous deepening of industrialization,the burning of fossil energy has emitted a large amount of carbon dioxide,which has caused many problems such as global warming and sea level rise.Among many ways to convert carbon dioxide,electrochemical reduction of carbon dioxide has attracted much attention.However,the higher overpotential and occurrence of side reactions have become the biggest limitation,which also makes the study of electroreduction carbon dioxide catalysts urgent.As a material with good chemical and thermal stability,boron nitride has been used as a supporting substrate in the field of catalysis.In recent years,with the discovery of the catalytic activity of hexagonal boron nitride for the oxidative dehydrogenation,researchers have gained a new understanding of the catalytic effect of boron nitride.This article is based on the preparation and doping of porous boron nitride microtube,and then applied it to the oxidative dehydrogenation of ethane and the electroreduction of carbon dioxide.The main research contents and results are as follows:(1)Preparation of porous boron nitride microtubes and its performance in catalyzing oxidative dehydrogenation of ethaneUsing melamine and boric acid as raw materials,a porous boron nitride micro-nano tube(BNMTs)was synthesized through a one-step reaction.The diameter of porous microtubes was between 200 nm and 1?m and the length can reach tens of microns.It had a rich pore structure,and the specific surface area can reach 350 m~2/g.Porous boron nitride microtubes exhibit excellent catalytic performance when catalyzing the oxidative dehydrogenation of ethane.They can achieve 45%ethane conversion and 72%ethylene selectivity at 600?,which are more than twice what commercial flake boron nitride.The further research and commercial application of boron nitride microtubes have great prospects because of their unique properties and relatively simple synthesis methods.(2)Preparation of gold nanoparticle-loaded boron nitride microtubes and its electrocatalytic reduction of carbon dioxideUsing porous boron nitride as the substrate,gold nanoparticles were successfully loaded on it by wet chemical impregnation,and the diameter of the gold nanoparticles was between 3 and 5 nm.The gold nanoparticle-loaded boron nitride microtubes was used as a catalyst for the electroreduction of carbon dioxide.At a voltage of -0.73V,the Faraday efficiency of the electrocatalysis to generate carbon monoxide can reach 70%.