The launch of International Thermonuclear Experimental Reactor project paves the way to wide adoption of DT fusion energy as future energy source.Efficient fuel cycle to minimize strategic tritium inventory proves cru...The launch of International Thermonuclear Experimental Reactor project paves the way to wide adoption of DT fusion energy as future energy source.Efficient fuel cycle to minimize strategic tritium inventory proves crucial for commercially viable fusion technologies.ZrCo alloy is considered as a promising candidate for fast isotope handling.However,cycling degradation caused by hydrogen-induced disproportionation results in severe tritium trapping,thus impeding its practical application.Herein,an isostructural transition is successfully constructed with low hysterisis,ameliorated plateau flatness of pressure-composition isotherms and improved high-temperature durability for hydrogen trapping minimization.Specifically,the optimal Zr_(0.7)Hf_(0.15)Nb_(0.15)Co_(0.6)Cu_(0.15)Ni_(0.25) alloy adopts Hf-Nb and Cu-Ni as Zr and Co side doping elements,exhibiting substantial thermodynamic destabilization with nearly 90℃ reduction of delivery temperature,and significant kinetic promotion with a threefold lower energy barrier.More importantly,both hydrogen utilization and cycling retention of optimal alloy are increased by about twenty times compared with pristine alloy after 100 cycles at 500℃.Minimized disproportionation driving force from both isostructural transition and suppressed 8e hydrogen occupation realizes full potential of optimal alloy.This work demonstrates the effectiveness of combining isostructural transformation and high-temperature durability improvement to enhance the hydrogen utilization of ZrCo-based alloys and other hydrogen storage materials.展开更多
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
基金supports from the National Key Research and Development Program of China(2022YFE03170002)the National Natural Science Foundation of China(52071286 and U2030208).
文摘The launch of International Thermonuclear Experimental Reactor project paves the way to wide adoption of DT fusion energy as future energy source.Efficient fuel cycle to minimize strategic tritium inventory proves crucial for commercially viable fusion technologies.ZrCo alloy is considered as a promising candidate for fast isotope handling.However,cycling degradation caused by hydrogen-induced disproportionation results in severe tritium trapping,thus impeding its practical application.Herein,an isostructural transition is successfully constructed with low hysterisis,ameliorated plateau flatness of pressure-composition isotherms and improved high-temperature durability for hydrogen trapping minimization.Specifically,the optimal Zr_(0.7)Hf_(0.15)Nb_(0.15)Co_(0.6)Cu_(0.15)Ni_(0.25) alloy adopts Hf-Nb and Cu-Ni as Zr and Co side doping elements,exhibiting substantial thermodynamic destabilization with nearly 90℃ reduction of delivery temperature,and significant kinetic promotion with a threefold lower energy barrier.More importantly,both hydrogen utilization and cycling retention of optimal alloy are increased by about twenty times compared with pristine alloy after 100 cycles at 500℃.Minimized disproportionation driving force from both isostructural transition and suppressed 8e hydrogen occupation realizes full potential of optimal alloy.This work demonstrates the effectiveness of combining isostructural transformation and high-temperature durability improvement to enhance the hydrogen utilization of ZrCo-based alloys and other hydrogen storage materials.
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.
