TiFe alloys are AB-based hydrogen storage materials with unique characteristics and a wide range of applications.However,the presence of impurity gases(such as O_(2),CO,CO_(2),and CH4)has a considerable impact on the ...TiFe alloys are AB-based hydrogen storage materials with unique characteristics and a wide range of applications.However,the presence of impurity gases(such as O_(2),CO,CO_(2),and CH4)has a considerable impact on the hydrogen storage capacity and kinetics of TiFe alloys,drastically limiting their practical application in hydrogen storage.Consequently,in this study,we investigated the hydrogen absorption kinetics and cycling performance of the TiFe_(0.9) alloy in the presence of common impurity gases(including CH4,CO,CO_(2),and O_(2))and determined the corresponding poisoning mechanisms.Specifically,we found that CH4 did not react with the alloy but acted through physical coverage.In contrast,CO and CO_(2) occupy the active sites for H_(2),significantly impeding the dissociation and absorption of H_(2).In addition,O_(2) reacts directly with the alloy to form a passivating layer that prevents hydrogen absorption.These findings were fur-ther corroborated by in situ Fourier transform infrared spectrometry(FTIR)and density functional theory(DFT).The relationship between the adsorption energies of the impurity gases and hydrogen obtained through DFT calculations complements the experimental results.Un-derstanding these poisoning behaviors is crucial for designing Ti-based high-entropy hydrogen storage alloy alloys with enhanced resist-ance to poisoning.展开更多
基金supported by the National Key Research&Development Program of China(No.2022YFB4004301)the National Natural Science Foundation of China(Nos.52201274 and 52307250)the Shaanxi Province key research and development plan,China(No.2024CY2-GJHX-53).
文摘TiFe alloys are AB-based hydrogen storage materials with unique characteristics and a wide range of applications.However,the presence of impurity gases(such as O_(2),CO,CO_(2),and CH4)has a considerable impact on the hydrogen storage capacity and kinetics of TiFe alloys,drastically limiting their practical application in hydrogen storage.Consequently,in this study,we investigated the hydrogen absorption kinetics and cycling performance of the TiFe_(0.9) alloy in the presence of common impurity gases(including CH4,CO,CO_(2),and O_(2))and determined the corresponding poisoning mechanisms.Specifically,we found that CH4 did not react with the alloy but acted through physical coverage.In contrast,CO and CO_(2) occupy the active sites for H_(2),significantly impeding the dissociation and absorption of H_(2).In addition,O_(2) reacts directly with the alloy to form a passivating layer that prevents hydrogen absorption.These findings were fur-ther corroborated by in situ Fourier transform infrared spectrometry(FTIR)and density functional theory(DFT).The relationship between the adsorption energies of the impurity gases and hydrogen obtained through DFT calculations complements the experimental results.Un-derstanding these poisoning behaviors is crucial for designing Ti-based high-entropy hydrogen storage alloy alloys with enhanced resist-ance to poisoning.
基金Project (2007BAE07B05) Supported by the National Key Technologies R&D Program of ChinaProject (50902115) Supported by the National Natural Science Foundation of China
