The Preparation Of SPE Membrane Electrode And The Regulation Of Selective Adsorption Of Hydrogen And Benzene

The hydrogen production/hydrogen storage integration technology can greatly improve the electrode selectivity and current efficiency in virtue of the good abilities of lower energy consumption,good ionic conductivity and so on.It can be used in many fields such as fuel cell,petrochemical and hydrogen energy preparation.The precondition for the application of hydrogen production/hydrogen storage integration technology is an solid polymer electrolyte（SPE）membrane electrode composed of Pt-based catalyst which has high catalytic activity and chemical stability.However,the application of pure Pt,used as catalyst,is limited by its disadvantages such as high cost,easy poisoning failure and so on,which also greatly reduce its catalytic activity.The key problem in the application of Pt catalysts is the relationship between the synthesis of Pt alloy catalysts and their effect on efficiency of catalytic hydrogaenation.In this work,PtNi/C and PtTi/C alloy catalysts were prepared by controlling the movement of the target site and deposition temperature,using ion beam sputtering（IBS）technology,determined the optimal contents of Ni and Ti and the key factors,for instance,the optimum deposition temperature.Then,the PtNi/C and PtTi/C were prepared with the Nafion membrane to obtain the SPE membrane electrode through hot pressing process.The hydrogen evolution resistance of the catalyst was characterized by linear scanning voltammetry（LSV）and electrochemical cyclic voltammetry（CV）.The surface morphology,phase and composition of the catalyst samples were characterized by X-ray diffraction（XRD）,inductively coupled plasma optical emission spectrometer（ICP-OES）and scanning electron microscopy equipped with energy dispersion spectrum（SEM&EDS）.The electrocatalytic hydrogenation of benzene and the benzene adsorption activation potential were characterized by EQCM.The hydrogenation performance of the SPE membrane electrode was tested by a benzene hydrogenation unit（liquid/liquid）.The results are as follows:（1）The electrochemical catalytic performance analysis shows that the hydrogen evolution inhibition effect of the PtNi/C and PtTi/C alloy catalysts prepared with a moving distance（ST）of45 mm is the most prominent.At this value of S_T,the best hydrogen evolution inhibition performance is exhibited provided that,the PtNi/C alloy catalyst is deposited at room temperature,and the Pt Ti/C alloy catalyst is deposited at 350°C.（2）Using PEG6000 alcohol solution with mass fraction of 0.3%as the electrolyte,the adsorption mass of benzene is the largest（211.6ng）.At the same time,it is determined that the activation potential of benzene is around-0.5V,and the mass is found by Electrochemical Quartz Crystal Microbalance（EQCM）analysis.（3）Analysis by benzene hydrogenation（liquid/liquid）at-0.5V electrolytic voltage shown:both SPE-N and SPE-T samples have excellent catalytic hydrogenation properties.Where J₀ of SPE-T is 2.39×10^-4A/cm²,which is 66.78%higher than that of SPE-N,the current efficiency of SPE-T（91.82%）is 11.38%higher than that of SPE-N.SPE-T The apparent activation energy of hydrogenation is 151.32 KJ/mol,which is 9.34%lower than that of SPE-N.These implies the hydrogenation performance of SPE-T alloy electrode is superior to that of SPE-N during the electrocatalytic hydrogenation of benzene,which provides some data support for the selection of alloy elements and the influence of composition control on the hydrogenation performance of Pt alloy SPE membrane electrode.