Based on ion chromatography technology, we have developed a new method that combines ion chromatography with a conductivity detector to separate and determine the substances of oxalic acid and glyoxalic acid, which ar...Based on ion chromatography technology, we have developed a new method that combines ion chromatography with a conductivity detector to separate and determine the substances of oxalic acid and glyoxalic acid, which are the main substances in the electrosynthesis of glyoxalic acid. The experimental results demonstrate that the detection sensitivity is ahead of 10 -6 grade, the cofficient of variation of retention time, the height of peak and the area of peak outperform 1%. All the recoveries of the detected substances are ranged between 98% and 102%. The method exhibits advantages of high selectivity, sensitivity, speediness and simple equipment. Furthermore, simultaneous determination of a mixture of several substances can be carried out by the method. We have demonstrated in the current paper that the ion chromatography is a speedy, effective, new detection method, which may be used to determine the substances existing in the electrosynthesis process of glyoxalic acid.展开更多
A typical electrode reaction of electro-organic synthesis usually takes place with competing side electrode reaction and homogeneous reaction.To enhance the electrode polarization for increasing reaction rate will con...A typical electrode reaction of electro-organic synthesis usually takes place with competing side electrode reaction and homogeneous reaction.To enhance the electrode polarization for increasing reaction rate will considerably reduce the reaction selectivity.Packed bed electrodes can reach higher current densities at relatively low electrode polarizations,which is favorable to mitigating the inconsistency between reaction rate and selectivity.In this paper,the typical process of electro-organic synthesis in a differential reactor of packed bed electrode(PBEDR),was theoretically analyzed with emphasis on the effect of lateral distribution of over-potential on the selectivity.A generalized mathematical model was developed to describe the distribution of over-potential.Dimensionless variables μ and that characterize the polarization and influence of side electrode reaction in the system,were derived from modeling.Adomian’s decomposition method(ADM)was used to solve the nonlinear differential equation of the model to obtain an approximate analytical solution,which was in the form of algebraic expressions of infinite power series.By the solution,the relationship between over-potential distribution and average selectivity could be easily calculated without solving the nonlinear model time and again.Finally,an analysis of electrochemical reduction of nitrobenzene in a PBEDR was presented,and the characteristic size of the reactor,namely the thickness of the packed bed electrode,was theoretically optimized.The results showed that the calculated results were consistent with experimental data satisfactorily.展开更多
文摘Based on ion chromatography technology, we have developed a new method that combines ion chromatography with a conductivity detector to separate and determine the substances of oxalic acid and glyoxalic acid, which are the main substances in the electrosynthesis of glyoxalic acid. The experimental results demonstrate that the detection sensitivity is ahead of 10 -6 grade, the cofficient of variation of retention time, the height of peak and the area of peak outperform 1%. All the recoveries of the detected substances are ranged between 98% and 102%. The method exhibits advantages of high selectivity, sensitivity, speediness and simple equipment. Furthermore, simultaneous determination of a mixture of several substances can be carried out by the method. We have demonstrated in the current paper that the ion chromatography is a speedy, effective, new detection method, which may be used to determine the substances existing in the electrosynthesis process of glyoxalic acid.
文摘A typical electrode reaction of electro-organic synthesis usually takes place with competing side electrode reaction and homogeneous reaction.To enhance the electrode polarization for increasing reaction rate will considerably reduce the reaction selectivity.Packed bed electrodes can reach higher current densities at relatively low electrode polarizations,which is favorable to mitigating the inconsistency between reaction rate and selectivity.In this paper,the typical process of electro-organic synthesis in a differential reactor of packed bed electrode(PBEDR),was theoretically analyzed with emphasis on the effect of lateral distribution of over-potential on the selectivity.A generalized mathematical model was developed to describe the distribution of over-potential.Dimensionless variables μ and that characterize the polarization and influence of side electrode reaction in the system,were derived from modeling.Adomian’s decomposition method(ADM)was used to solve the nonlinear differential equation of the model to obtain an approximate analytical solution,which was in the form of algebraic expressions of infinite power series.By the solution,the relationship between over-potential distribution and average selectivity could be easily calculated without solving the nonlinear model time and again.Finally,an analysis of electrochemical reduction of nitrobenzene in a PBEDR was presented,and the characteristic size of the reactor,namely the thickness of the packed bed electrode,was theoretically optimized.The results showed that the calculated results were consistent with experimental data satisfactorily.
