Research Of Efficient Platinum Gas Diffussion Catalyst Which Applied To NO_x Removal In Low Temperature

The amount of nitrogen oxide(NOx)in atmosphere is increasing fiercely as a result of human activities,causing the increasingly serious environmental problem.The effective of the NOx emission become the urgent demand,however,the existing NOx control technologies are increasingly difficult to respond to these demand.A new Gas Diffusion Reactor which was applied to H2-SCR process is proposed in this paper on the base of achievement in existence,developing Pt-transition metal binary alloy catalysts which own high catalytically active in low temperature,then the effect of oxygen,hydrogen content and catalysts component on the performance of the catalysts were investigated.Finally,combining with the actual conditions of this subject,an evaluation indicator system for synthetically evaluating the performance of catalysts from various angles was established,some optimum and potential catalysts were selected according to the evaluation result.The performance of Pt/C catalysts,which were synthesized by hydrothermal method,were poor in low temperature,but the NO conversion could exceed 90%and exhibited a good resistance to SO2 when the reaction temperature was over 120?,H2O took a positive role for NO conversion in this system.According to the result of XRD and XPS analysis,we got different Pt-transition metal binary alloy catalysts by using the improving hydrothermal method.Benefit from this special structure,comparing with Pt/C,the performance of new binary alloy catalysts improved in different degree.NO could be removed completely over Pt-Ni catalysts in 60?.The effect of O2 on the performance of catalysts was very complicated,it was affected by the reaction temperature,H2 content and catalysts component.Generally speaking,the higher reaction temperature or H2 content,the lower inhibitory effect on the catalysts.As a reducing agent,increasing H2 concentration was good for NO conversion process,however,affected by O2 and temperature,the sensitivitese of different catalysts to the change of H2 content were different.Different catalysts component can bring different performance,Pt and transition metal coexist in catalysts,in good proportions,was important to maximized performance.We evaluated the performance of catalysts by using evaluation system,according to this result,we selected the best catalyst.Result showed that the performance of Pt-Ni binary alloy catalysts were much better than the other three types,especially for Pt2Ni/C catalyst,which was recognized as one of the most potential catalyst.Pt-Fe binary alloy catalysts came second and PtFe/C catalyst show good performance.Among Pt-Cu binary alloy catalysts,Pt2Cu/C showed the best performance,just after Pt2Ni/C,but other Pt-Cu catalysts show poor performance.The performance of Pt-Co binary alloy catalysts were poor generally.