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Synthesis Ammonia Electrically At Atmospheric Pressure And Low Temperature With Proton Exchange Membrane

Posted on:2009-12-08Degree:MasterType:Thesis
Country:ChinaCandidate:J WangFull Text:PDF
GTID:2132360245985467Subject:Physical chemistry
Abstract/Summary:PDF Full Text Request
Ammonia is an important material as the final or intermediate product. Currently, the traditional method for ammonia synthesis is used Haber's method generally, which is used at higher pressure and higher temperature with catalyst because of the limit of kinetics. Thus there is a stringent requirement for the equipment and the rate of evolution of ammonia cannot be improved, and it needs more costly energy. With the increasing demand for ammonia and the increasing problems for energy and environment pollution progressively, a new way is demanded for synthesis of ammonia with high yield, low energy consumption, and the global sustainable development.Synthesis ammonia electrically at atmospheric pressure has received much attention since firstly reported and published in《SCIENCE》,at 1995 by George Marnllos,which surmount the limit of thermodynamics in traditional Haber method of ammonia synthesis and blaze a new trail for the industry of ammonia synthesis.Ammonia was synthesized with proton exchange membrane at atmospheric pressure and low temperature in the homemade cell reactor in terms of electrochemistry in this parper,which includes two parts: review section and experimental section.In review section,the most important key of the fuel cell—proton exchange membrane is presented in this paper,a brief overview is given of types and application,prospects are summarized.Being major subject, the fluorosulfonic exchange membrane( Nafion membrane) and Sulfonated Polysulfone proton exchange membrane are reviewed concerning their structure properties,conductivities and progress as well as study status.In experimental section, The reconstructive sulfonated polysulfone proton exchange membrane (SPSPEM) was prepared by sulfonation reaction using ethylene dichloride as solvent and chlorosulfonic acid as sulfonating reagen, the precursor of all kinds of anode and cathode(Sm0.5Sr0.5CoO3-δ,Ba0.5Sr0.5CoO0.8Fe0.2O3-δ,LaFe0.7Cu0.1Ni0.2O3-δ,La0.8Sr0.2CoO0.8Fe0.2 O3-δ,La0.75Sr0.25Cr0.5Mn0.5O3-δ, NiO-Ce0.85m0.2O1.9)was synthesized by the gol-gel method,then sintered at hightemperature.The topography was characterized with transmission electron microscopy (TEM) and Scanning electron microscopy(SEM).The phase was confirmed by power X-ray diffraction(XRD).Ammonia was synthesized from nitrogen and hydrogen/natural gas at atmospheric pressure and low temperature in a single cell reactor by electrochemical methods,the single cell was integrated by proton exchange membrane (SPSPEM) and all kinds of anode and cathode.Ammonia was synthesized not only from hydrogen and nitrogen but also natural gas and nitrogen at atmospheric pressure and low temperature in the cell reactor.The research breakthrough in ammonia synthesis from natural gas has important significance,because natural gas can offer many advantage in comparison to hydrogen.For example,it is relatively abundant and widely available around the world.The optimum temperature and,voltage and potential factor are studied as the function of rates of ammonia formation.And all of the samples produce ammonia to different degrees,and the rates of ammonia formation are up to 10-9mol.s-1.cm-2.there are lots of work to do in synthesizing ammonia at atmospheric pressure and low temperature with proton exchange membrane in the future.In this paper,problems,possible solutions and future opportunities for further development are given.
Keywords/Search Tags:sulfonated polysulfone proton exchange membrane, Nafion membrane, atmospheric pressure and low temperature, synthesizing ammonia
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