Preparation And Properties Of Proton-Electronic Dual-Phase Composite Membrane For Hydrogen Separation

Hydrogen is an important raw material in industrial production,and it is also a green and renewable energy.However,there is no free hydrogen in nature due to the activity of hydrogen,which is mainly obtained by coal chemical industry and petroleum processing,and it is difficult to obtain pure hydrogen directly.Therefore,the separation and purification of hydrogen has become a key technology in the application of hydrogen energy.The membrane separation method is the hotpot among many methods in the current research.However,the existing hydrogen separation membrane has some disadvantages,such as the expensive palladium membrane,the high temperature of proton conductor ceramic membrane using.In view of this,a proton-electron hybrid conductive biphasic composite membrane for hydrogen separation at low temperature was developed.First,different sulfonation degrees of the sulfonated polyether ether ketone（SPEEK）were prepared from PEEK with concentrated sulfuric acid as sulfonating reagent.It mainly studied the effects of sulfonation temperature and time on the sulfonation degree and performance of SPEEK membrane.The results showed that the higher the sulfonation temperature,the faster the sulfonation rate.The longer the sulfonation time,the greater the sulfonation degree of SPEEK;At 60℃,after 3～7 h of sulfonation,the sulfonation degree of SPEEK was between51.1%～85.4%.With the increase of SPEEK sulfonation degree,the hydroscopicity and swelling degree of SPEEK membrane increased.The mechanical property of SPEEK membrane was reduced.According to these properties,the synthetic sulfonation degree of SPEEK was 72%as the proton conductive phase of the composite membrane.Then,SPEEK with 72% sulfonation degree was used as the proton conductive phase,and ascorbic acid reduced graphene oxide（rGO）was used as the electronic conductive phase.The SPEEK and rGO biphasic composite membranes were prepared by casting and solvent evaporation.The effect of rGO doping amount on the structure and hydrogen permeability of SPEEK-rGO two-phase composite membrane was mainly investigated.The results show that the doping of rGO improves the mechanical strength of the membrane,but with the increase of the doping amount of rGO,agglomeration occurs in the membrane;the hydrogen permeation results show that the hydrogen permeability of the dual-phase composite membrane doped with 3 wt%rGO Preferably,at 300℃,its hydrogen permeation rate was 0.089 m L·min^-1·cm^-2;and it can be stably operated at 240℃ for 100 h.By doping phosphoric tungstic acid（HPW）in the SPEEK-rGO biphasic composite membrane,the dense SPEEK-HPW-rGO composite membrane was prepared by casting combined with solvent volatilization,and the doping amount of HPW on the composite membrane structure was mainly investigated And performance impact.SEM and EDX characterization results show that HPW was uniformly dispersed in the membrane;hydrogen permeation performance measurement shows that the hydrogen permeation rate of the composite membrane increases with increasing HPW doping amount;the hydrogen permeation rate of the dual-phase composite membrane was also it increases with the increase of hydrogen partial pressure;at 300℃,the hydrogen permeation rate of the biphase composite membrane doped with 50 wt%HPW was 0.15 m L·min^-1·cm^-2,and it can run stably at 240℃ for 120h.