Efficient capture,safe storage and release of tritium from the international thermonuclear experimental reactor(ITER) reaction exhaust gas is a perplexing problem,and the development of an efficient tritium-getter mat...Efficient capture,safe storage and release of tritium from the international thermonuclear experimental reactor(ITER) reaction exhaust gas is a perplexing problem,and the development of an efficient tritium-getter material with ultra-low hydrogenation equilibrium pressure is considered as a reliable way.In this work,Zr_(2)Co alloy was selected as a tritium-getter material and prepared through induction levitation melting.Fundamental performance test results show that Zr_(2)Co exhibits an ultra-low hydrogenation equilibrium pressure of 3.22 × 10^(-6) Pa at 25℃ and excellent hydriding kinetics under a low hydrogen pressure of 0.005 MPa.Interestingly,unique phase transition behaviors were presented in Zr_(2)Co-H system.Specifically,Zr_(2)CoH_(5) formed by Zr_(2)Co hydrogenated at room temperature is initially decomposed into ZrH_(2) and ZrCoH_(3) at200 ℃.With the temperature increasing to 350 ℃,ZrCoH_(3)is dehydrogenated to ZrCo,and then ZrCo further reacts with ZrH_(2) at 650 ℃ to reform Zr_(2)Co and hydrogen.Among the staged phase transition pathways during dehydrogenation,the decomposition of Zr_(2)CoH_(5) occurs preferentially,which is well accordance with both the smallest reaction energy barrier and the maximum reaction spontaneity that are determined respectively from kinetics activation energy and thermodynamics Gibbs free energy.Furthermore,first principles calculation results indicate that the stronger binding of hydrogen in interstitial environments of ZrCoH_(3)and ZrH_(2) triggers the hydrogen-stabilized phase transformation of Zr_(2)CoH_(5).The unique phase transition mechanisms in Zr_(2)Co-H system can shed light on the further exploration and regulation of analogous staged phase transition of hydrogen storage materials.展开更多
Electrocatalytic water splitting coupled with sustainable energies is identified as an environmentally friendly and renewable strategy to generate high-quality hydrogen for the fuel cells.However,the main challenge is...Electrocatalytic water splitting coupled with sustainable energies is identified as an environmentally friendly and renewable strategy to generate high-quality hydrogen for the fuel cells.However,the main challenge is to develop high performance,low cost and chemically stable electrocatalysts to decline the energy barriers and enhance the sluggish kinetics of hydrogen evolution reaction(HER).Herein,a three-dimensional hierarchically ordered macroporous Ru-CoP@NC electrocatalyst(3DOM Ru-CoP@NC)derived from ordered macro-microporous metal-organic frameworks has been prepared using the precursor@template and double-solvent methods.The prepared 3DOM Ru-CoP@NC catalyst exhibits an overpotential of 15 mV(j=10 mA·cm^(-2))and a reaction Tafel slope of 38 mV·dec^(-1)in alkaline electrolyte,which are superior to commercial Pt@C catalyst.Additionally,the overpotential and reaction Tafel slope of this catalyst in acidic media are 45 mV and 50 mV·dec^(-1),respectively.The outstanding HER activities of 3DOM Ru-CoP@NC catalysts are ascribed to the 3D highly interconnectedreticular nanospaces that can increase effective reaction active sites.The N dope d carbon framework improves the electronic properties and conductivity.Moreover,the strong interaction of Ru and CoP nanoparticles also boosts the HER process.These results indicate that 3DOM Ru-CoP@NC catalysts with high catalytic activities have a broad application prospect in the future.展开更多
Nanoscale CeAl4 was directly synthesized by the thermal reaction between CeH2 and nano-aluminum at300℃.Then nano CeAl4-doped sodium alanate(NaAlH4)was synthesized by ball milling NaH/Al with 0.04CeAl4under hydrogen...Nanoscale CeAl4 was directly synthesized by the thermal reaction between CeH2 and nano-aluminum at300℃.Then nano CeAl4-doped sodium alanate(NaAlH4)was synthesized by ball milling NaH/Al with 0.04CeAl4under hydrogen atmosphere at room temperature,and the catalytic efficiency of nanoscale CeAl4 for hydrogen storage of NaAlH4 was systematically investigated.It is shown that CeAl4 can effectively improve the dehydrogenation properties of sodium alanate system.The 0.04CeAl4-doped NaAlH4 system starts to release hydrogen below 80℃,completes dehydrogenation within 10 min at 170℃,and exhibits good cycling de/hydrogenation kinetics at relatively lower temperature(100-140℃).Apparent activation energy of the dehydrogenation of NaAlH4 can be effectively reduced by addition of CeAl4,resulting in the decrease in desorption temperatures.Moreover,by analyzing the reaction kinetics of nano CeAl4-doped NaAlH4sample,both of the decomposition steps are conformed to a two-dimensional phase-boundary growth mechanism.The mechanistic investigations gained here can help to understand the de-/rehydrogenation behaviors of catalyzed complex metal hydride systems.展开更多
Metal hydride with proper hydrogen storage properties is the key component of hydride thermal hydrogen compressor.In this work,Ti_(0.85)Zr_(0.17)(Cr-Mn-V)_(1.3)Fe_(0.7)-based alloys were developed to achieve thermal h...Metal hydride with proper hydrogen storage properties is the key component of hydride thermal hydrogen compressor.In this work,Ti_(0.85)Zr_(0.17)(Cr-Mn-V)_(1.3)Fe_(0.7)-based alloys were developed to achieve thermal hydrogen compression at mild operating temperatures of water bath.The results indicate the single C 14-type Laves phase as well as homogeneously distributed elements of all alloys.With increased Mn content in Ti_(0.85)Zr_(0.17)Cr_(1.2-x)Mn_xFe_(0.7)V_(0.1)(x=0,0.1,0.2,0.3)alloys.展开更多
基金financially supported by the National Key Research and Development Program of China (No.2022YFE03170002)the National Natural Science Foundation of China (Nos.52071286 and U2030208)。
文摘Efficient capture,safe storage and release of tritium from the international thermonuclear experimental reactor(ITER) reaction exhaust gas is a perplexing problem,and the development of an efficient tritium-getter material with ultra-low hydrogenation equilibrium pressure is considered as a reliable way.In this work,Zr_(2)Co alloy was selected as a tritium-getter material and prepared through induction levitation melting.Fundamental performance test results show that Zr_(2)Co exhibits an ultra-low hydrogenation equilibrium pressure of 3.22 × 10^(-6) Pa at 25℃ and excellent hydriding kinetics under a low hydrogen pressure of 0.005 MPa.Interestingly,unique phase transition behaviors were presented in Zr_(2)Co-H system.Specifically,Zr_(2)CoH_(5) formed by Zr_(2)Co hydrogenated at room temperature is initially decomposed into ZrH_(2) and ZrCoH_(3) at200 ℃.With the temperature increasing to 350 ℃,ZrCoH_(3)is dehydrogenated to ZrCo,and then ZrCo further reacts with ZrH_(2) at 650 ℃ to reform Zr_(2)Co and hydrogen.Among the staged phase transition pathways during dehydrogenation,the decomposition of Zr_(2)CoH_(5) occurs preferentially,which is well accordance with both the smallest reaction energy barrier and the maximum reaction spontaneity that are determined respectively from kinetics activation energy and thermodynamics Gibbs free energy.Furthermore,first principles calculation results indicate that the stronger binding of hydrogen in interstitial environments of ZrCoH_(3)and ZrH_(2) triggers the hydrogen-stabilized phase transformation of Zr_(2)CoH_(5).The unique phase transition mechanisms in Zr_(2)Co-H system can shed light on the further exploration and regulation of analogous staged phase transition of hydrogen storage materials.
基金financially supported by the National Natural Science Foundation of China(Nos.U20A20237,52371218,51863005,52271205,51871065,51971068and52101245)the Scientific Research and Technology Development Program of Guangxi(Nos.AA19182014,AD 17195073,AA17202030-1,AB21220027 and 2021AB17045)+6 种基金the National Natural Science Foundation of Guangxi Province(Nos.2021GXNSFBA075057,2018GXNSFDA281051,2014GXNSFAA118401 and 2013GXNSFBA019244)the Scientific Research and Technology Development Program of Guilin(Nos.20210102-4 and 20210216-1)Guangxi Bagui Scholar FoundationGuilin Lijiang Scholar FoundationGuangxi Collaborative Innovation Centre of Structure and Property for New Energy and MaterialsGuangxi Advanced Functional Materials FoundationApplication Talents Small Highlands and Chinesisch-Deutsche Kooperationsgruppe(No.GZ1528)。
文摘Electrocatalytic water splitting coupled with sustainable energies is identified as an environmentally friendly and renewable strategy to generate high-quality hydrogen for the fuel cells.However,the main challenge is to develop high performance,low cost and chemically stable electrocatalysts to decline the energy barriers and enhance the sluggish kinetics of hydrogen evolution reaction(HER).Herein,a three-dimensional hierarchically ordered macroporous Ru-CoP@NC electrocatalyst(3DOM Ru-CoP@NC)derived from ordered macro-microporous metal-organic frameworks has been prepared using the precursor@template and double-solvent methods.The prepared 3DOM Ru-CoP@NC catalyst exhibits an overpotential of 15 mV(j=10 mA·cm^(-2))and a reaction Tafel slope of 38 mV·dec^(-1)in alkaline electrolyte,which are superior to commercial Pt@C catalyst.Additionally,the overpotential and reaction Tafel slope of this catalyst in acidic media are 45 mV and 50 mV·dec^(-1),respectively.The outstanding HER activities of 3DOM Ru-CoP@NC catalysts are ascribed to the 3D highly interconnectedreticular nanospaces that can increase effective reaction active sites.The N dope d carbon framework improves the electronic properties and conductivity.Moreover,the strong interaction of Ru and CoP nanoparticles also boosts the HER process.These results indicate that 3DOM Ru-CoP@NC catalysts with high catalytic activities have a broad application prospect in the future.
基金financially supported by the National High Technology Research&Development Program of China(No.2012AA051503)the National Natural Science Foundation of China(Nos.51171173 and 51471151)+2 种基金the China Postdoctoral Science Foundation(No.2012M521167)the Program for Innovative Research Team in University of Ministry of Education of China(No.IRT13037)the Zhejiang Provincial Science&Technology Program of China(Nos.2014C31134 and 2015C31035)
文摘Nanoscale CeAl4 was directly synthesized by the thermal reaction between CeH2 and nano-aluminum at300℃.Then nano CeAl4-doped sodium alanate(NaAlH4)was synthesized by ball milling NaH/Al with 0.04CeAl4under hydrogen atmosphere at room temperature,and the catalytic efficiency of nanoscale CeAl4 for hydrogen storage of NaAlH4 was systematically investigated.It is shown that CeAl4 can effectively improve the dehydrogenation properties of sodium alanate system.The 0.04CeAl4-doped NaAlH4 system starts to release hydrogen below 80℃,completes dehydrogenation within 10 min at 170℃,and exhibits good cycling de/hydrogenation kinetics at relatively lower temperature(100-140℃).Apparent activation energy of the dehydrogenation of NaAlH4 can be effectively reduced by addition of CeAl4,resulting in the decrease in desorption temperatures.Moreover,by analyzing the reaction kinetics of nano CeAl4-doped NaAlH4sample,both of the decomposition steps are conformed to a two-dimensional phase-boundary growth mechanism.The mechanistic investigations gained here can help to understand the de-/rehydrogenation behaviors of catalyzed complex metal hydride systems.
基金financially supported by the National Key Research and Development Program of China (No. 2019YFB1505100)the National Natural Science Foundation of China (No.U20A20237)Zhejiang Provincial Natural Science Foundation of China (No.LZ21E010002)
文摘Metal hydride with proper hydrogen storage properties is the key component of hydride thermal hydrogen compressor.In this work,Ti_(0.85)Zr_(0.17)(Cr-Mn-V)_(1.3)Fe_(0.7)-based alloys were developed to achieve thermal hydrogen compression at mild operating temperatures of water bath.The results indicate the single C 14-type Laves phase as well as homogeneously distributed elements of all alloys.With increased Mn content in Ti_(0.85)Zr_(0.17)Cr_(1.2-x)Mn_xFe_(0.7)V_(0.1)(x=0,0.1,0.2,0.3)alloys.