Synthesis And Desulfurization Performance Of 3DOM Copper Oxide Based Composite Desulfurizer At Ambient Temperature

Faced with increasingly serious environmental pollution problems and gradually harsh air protection law,improve energy efficiency,the development of efficient,green,energy-saving new technology is imminent.Fuel cell is one of the outstanding representatives.The rise of hydrogen fuel cells makes the low temperature desulfurization into the people's vision.In order to meet the normal operation of the fuel cell,it is necessary to carry out the desulfurization of the hydrogen-rich gas supplying the fuel cell.Metal oxide adsorption desulfurization due to high precision?process operation is simple and widely used.Among them,the desulfurization thermodynamic advantages of copper oxide and zinc oxide are obvious,and it has a high desulfurization precision.However,there is a problem that the activity is poor and the sulfur capacity is low under normal temperature operation.Based on the previous research results,this study will improve the desulfurization performance of sulfur-based sulfide on the desulfurization performance of copper sulfide-based desulfurizer by texture optimization and surface modification.In this study,three-dimensional ordered macroporous copper-silicon and copper-zinc-silicon composite desulfurizer were prepared by colloidal crystal template method.The surface was modified by ammonia vapor deposition method and alkali impregnation method.The desulfurizers perform a dynamic evaluation experiment in a fixed bed,and then were characterized by scanning electron microscope?SEM?,transmission electron microscope?TEM?,X-ray diffraction?XRD?,nitrogen adsorption,CO₂-temperature programmed desorption?CO₂-TPD?,X-ray photoelectron spectroscopy?XPS?and X-ray absorption near edge structure?XANES?,thermal analyzer coupled with a mass spectrometry?TG-MS?,and the following conclusions were obtained:SEM,TEM,XRD and BET correlated results indicate that the macroporous structure with three-dimensional ordered macroporous structure is neat and orderly,and the three-dimensional space is interconnected,and the grain size is dispersed and the specific surface area is large.The addition of silica to the threedimensional ordered macroporous framework make the structure strong,while the active metal oxide plays a role in dispersion.The experimental results show that the special structure of three-dimensional ordered macroporous can make the sulfur capacity of copper-silicon composite desulfurizer increase six times,which highlights the role of macroporous in desulfurization process.The addition of water vapor during the desulfurization process plays a crucial role,the formation of the water film provides a great help for the dissociation and adsorption of hydrogen sulfide on the surface of the metal oxide.When the relative humidity is 47.6%,desulfurization agent desulfurization performance is best,sulfur capacity is 147 mg/g.However,due to the limited thermodynamic equilibrium,the addition of water vapor makes the desulfurization precision somewhat reduced.By modifying the surface of the desulfurizer by ammonization/alkalization,the above disadvantages can be overcome,and the desulfurization performance of the desulfurizer in a water atmosphere can be remarkably improved,and the precision and sulfur capacity can be greatly improved.The study shows that the desulfurizers with three-dimensional ordered macroporous regeneration at different temperatures has better activity than non-3DOM desulfurizer.After 300 oC regeneration,the desulfurizer has the best regeneration performance and maintains high sulfur capacity during the desulfurization/regeneration cycles.Through the study of copper-zinc-silicon composite desulfurizer,it is found that the sulfur capacity of copper-zinc-silicon composite desulfurizer is between zinc-silicon composite desulfurizer and copper-silicon composite desulfurizer? The 1% of copper and zinc-silicon composite' sulfur capacity is highest in the series of the copper-zinc-silicon composite desulfurizers,so that the interaction between the metals has a significant impact on its desulfur performance.