Artificial photocatalysis represents a hopeful avenue for tackling the global crisis of environmental and energy sustainability.The crux of industrial application in photocatalysis lies in efficient photocatalysts tha...Artificial photocatalysis represents a hopeful avenue for tackling the global crisis of environmental and energy sustainability.The crux of industrial application in photocatalysis lies in efficient photocatalysts that can inhibit the recombination of photogenerated charge carriers,thereby boost the efficiency of chemical reactions.In the past decade,single-atom catalysts(SACs)have been growing extremely rapidly and have become the forefront of photocatalysis owing to their superior utilization of metal atoms and outstanding catalytic activity.In this work,we provide an overview of the latest advancements and challenges in SACs for photocatalysis,focusing on the photocatalytic mechanisms,encompassing the generation,separation,migration,and surface extraction of photogenerated carriers.We also explore the design,synthesis,and characterization of SACs and introduce the progress of SACs for photocatalytic applications,such as water splitting and CO_(2)reduction.Lastly,we offer our personal perspectives on the opportunities and challenges of SACs in photocatalysis,aiming to provide insights into the future studies of SACs for photocatalytic applications.展开更多
为解决由于固定温度SAC(Soft Actor Critic)算法中存在的Q函数高估可能会导致算法陷入局部最优的问题,通过深入分析提出了一个稳定且受限的SAC算法(SCSAC:Stable Constrained Soft Actor Critic)。该算法通过改进最大熵目标函数修复固...为解决由于固定温度SAC(Soft Actor Critic)算法中存在的Q函数高估可能会导致算法陷入局部最优的问题,通过深入分析提出了一个稳定且受限的SAC算法(SCSAC:Stable Constrained Soft Actor Critic)。该算法通过改进最大熵目标函数修复固定温度SAC算法中的Q函数高估问题,同时增强算法在测试过程中稳定性的效果。最后,在4个OpenAI Gym Mujoco环境下对SCSAC算法进行了验证,实验结果表明,稳定且受限的SAC算法相比固定温度SAC算法可以有效减小Q函数高估出现的次数并能在测试中获得更加稳定的结果。展开更多
虚拟电厂(virtual power plant,VPP)作为多能流互联的综合能源网络,已成为中国加速实现双碳目标的重要角色。但VPP内部资源协同低碳调度面临多能流的耦合程度紧密、传统碳交易模型参数主观性强、含高维动态参数的优化目标在线求解困难...虚拟电厂(virtual power plant,VPP)作为多能流互联的综合能源网络,已成为中国加速实现双碳目标的重要角色。但VPP内部资源协同低碳调度面临多能流的耦合程度紧密、传统碳交易模型参数主观性强、含高维动态参数的优化目标在线求解困难等问题。针对这些问题,文中提出一种融合注意力机制(attention mechanism,AM)与柔性动作评价(soft actor-critic,SAC)算法的VPP多能流低碳调度方法。首先,根据VPP的随机碳流特性,面向动态参数建立基于贝叶斯优化的改进阶梯型碳交易机制。接着,以经济效益和碳排放量为目标函数构建含氢VPP多能流解耦模型。然后,考虑到该模型具有高维非线性与权重参数实时更新的特征,利用融合AM的改进SAC深度强化学习算法在连续动作空间对模型进行求解。最后,对多能流调度结果进行仿真分析和对比实验,验证了文中方法的可行性及其相较于原SAC算法较高的决策准确性。展开更多
Atomically dispersed catalysts exhibit significant influence on facilitating the sluggish oxygen reduction reaction(ORR)kinetics with high atom economy,owing to remarkable attributes including nearly 100%atomic utiliz...Atomically dispersed catalysts exhibit significant influence on facilitating the sluggish oxygen reduction reaction(ORR)kinetics with high atom economy,owing to remarkable attributes including nearly 100%atomic utilization and exceptional catalytic functionality.Furthermore,accurately controlling atomic physical properties including spin,charge,orbital,and lattice degrees of atomically dispersed catalysts can realize the optimized chemical properties including maximum atom utilization efficiency,homogenous active centers,and satisfactory catalytic performance,but remains elusive.Here,through physical and chemical insight,we review and systematically summarize the strategies to optimize atomically dispersed ORR catalysts including adjusting the atomic coordination environment,adjacent electronic orbital and site density,and the choice of dual-atom sites.Then the emphasis is on the fundamental understanding of the correlation between the physical property and the catalytic behavior for atomically dispersed catalysts.Finally,an overview of the existing challenges and prospects to illustrate the current obstacles and potential opportunities for the advancement of atomically dispersed catalysts in the realm of electrocatalytic reactions is offered.展开更多
Lithium metal batteries are regarded as prominent contenders to address the pressing needs owing to the high theoretical capacity.Toward the broader implementation,the primary obstacle lies in the intricate multi-elec...Lithium metal batteries are regarded as prominent contenders to address the pressing needs owing to the high theoretical capacity.Toward the broader implementation,the primary obstacle lies in the intricate multi-electron,multi-step redox reaction associated with sluggish conversion kinetics,subsequently giving rise to a cascade of parasitic issues.In order to smooth reaction kinetics,catalysts are widely introduced to accelerate reaction rate via modulating the energy barrier.Over past decades,a large amount of research has been devoted to the catalyst design and catalytic mechanism exploration,and thus the great progress in electrochemical performance has been realized.Therefore,it is necessary to make a comprehensive review toward key progress in catalyst design and future development pathway.In this review,the basic mechanism of lithium metal batteries is provided along with corresponding advantages and existing challenges detailly described.The main catalysts employed to accelerate cathode reaction with emphasis on their catalytic mechanism are summarized as well.Finally,the rational design and innovative direction toward efficient catalysts are suggested for future application in metal-sulfur/gas battery and beyond.This review is expected to drive and benefit future research on rational catalyst design with multi-parameter synergistic impacts on the activity and stability of next-generation metal battery,thus opening new avenue for sustainable solution to climate change,energy and environmental issues,and the potential industrial economy.展开更多
The rational design of metal single-atom catalysts(SACs)for electrochemical nitrogen reduction reaction(NRR)is challenging.Two-dimensional metal-organic frameworks(2DMOFs)is a unique class of promising SACs.Up to now,...The rational design of metal single-atom catalysts(SACs)for electrochemical nitrogen reduction reaction(NRR)is challenging.Two-dimensional metal-organic frameworks(2DMOFs)is a unique class of promising SACs.Up to now,the roles of individual metals,coordination atoms,and their synergy effect on the electroanalytic performance remain unclear.Therefore,in this work,a series of 2DMOFs with different metals and coordinating atoms are systematically investigated as electrocatalysts for ammonia synthesis using density functional theory calculations.For a specific metal,a proper metal-intermediate atoms p-d orbital hybridization interaction strength is found to be a key indicator for their NRR catalytic activities.The hybridization interaction strength can be quantitatively described with the p-/d-band center energy difference(Δd-p),which is found to be a sufficient descriptor for both the p-d hybridization strength and the NRR performance.The maximum free energy change(ΔG_(max))andΔd-p have a volcanic relationship with OsC_(4)(Se)_(4)located at the apex of the volcanic curve,showing the best NRR performance.The asymmetrical coordination environment could regulate the band structure subtly in terms of band overlap and positions.This work may shed new light on the application of orbital engineering in electrocatalytic NRR activity and especially promotes the rational design for SACs.展开更多
Atom-level modulation of the coordination environment for single-atom catalysts(SACs)is considered as an effective strategy for elevating the catalytic performance.For the MNxsite,breaking the symmetrical geometry and...Atom-level modulation of the coordination environment for single-atom catalysts(SACs)is considered as an effective strategy for elevating the catalytic performance.For the MNxsite,breaking the symmetrical geometry and charge distribution by introducing relatively weak electronegative atoms into the first/second shell is an efficient way,but it remains challenging for elucidating the underlying mechanism of interaction.Herein,a practical strategy was reported to rationally design single cobalt atoms coordinated with both phosphorus and nitrogen atoms in a hierarchically porous carbon derived from metal-organic frameworks.X-ray absorption spectrum reveals that atomically dispersed Co sites are coordinated with four N atoms in the first shell and varying numbers of P atoms in the second shell(denoted as Co-N/P-C).The prepared catalyst exhibits excellent oxygen reduction reaction(ORR)activity as well as zinc-air battery performance.The introduction of P atoms in the Co-SACs weakens the interaction between Co and N,significantly promoting the adsorption process of ^(*)OOH,resulting in the acceleration of reaction kinetics and reduction of thermodynamic barrier,responsible for the increased intrinsic activity.Our discovery provides insights into an ultimate design of single-atom catalysts with adjustable electrocatalytic activities for efficient electrochemical energy conversion.展开更多
基金supported by the National Natural Science Foundation of China(grant nos.52202099,52170042)the Beijing Natural Science Foundation(8222055)the Natural Science Foundation of Jilin Province(YDZJ202301ZYTS277).
文摘Artificial photocatalysis represents a hopeful avenue for tackling the global crisis of environmental and energy sustainability.The crux of industrial application in photocatalysis lies in efficient photocatalysts that can inhibit the recombination of photogenerated charge carriers,thereby boost the efficiency of chemical reactions.In the past decade,single-atom catalysts(SACs)have been growing extremely rapidly and have become the forefront of photocatalysis owing to their superior utilization of metal atoms and outstanding catalytic activity.In this work,we provide an overview of the latest advancements and challenges in SACs for photocatalysis,focusing on the photocatalytic mechanisms,encompassing the generation,separation,migration,and surface extraction of photogenerated carriers.We also explore the design,synthesis,and characterization of SACs and introduce the progress of SACs for photocatalytic applications,such as water splitting and CO_(2)reduction.Lastly,we offer our personal perspectives on the opportunities and challenges of SACs in photocatalysis,aiming to provide insights into the future studies of SACs for photocatalytic applications.
文摘为解决由于固定温度SAC(Soft Actor Critic)算法中存在的Q函数高估可能会导致算法陷入局部最优的问题,通过深入分析提出了一个稳定且受限的SAC算法(SCSAC:Stable Constrained Soft Actor Critic)。该算法通过改进最大熵目标函数修复固定温度SAC算法中的Q函数高估问题,同时增强算法在测试过程中稳定性的效果。最后,在4个OpenAI Gym Mujoco环境下对SCSAC算法进行了验证,实验结果表明,稳定且受限的SAC算法相比固定温度SAC算法可以有效减小Q函数高估出现的次数并能在测试中获得更加稳定的结果。
文摘虚拟电厂(virtual power plant,VPP)作为多能流互联的综合能源网络,已成为中国加速实现双碳目标的重要角色。但VPP内部资源协同低碳调度面临多能流的耦合程度紧密、传统碳交易模型参数主观性强、含高维动态参数的优化目标在线求解困难等问题。针对这些问题,文中提出一种融合注意力机制(attention mechanism,AM)与柔性动作评价(soft actor-critic,SAC)算法的VPP多能流低碳调度方法。首先,根据VPP的随机碳流特性,面向动态参数建立基于贝叶斯优化的改进阶梯型碳交易机制。接着,以经济效益和碳排放量为目标函数构建含氢VPP多能流解耦模型。然后,考虑到该模型具有高维非线性与权重参数实时更新的特征,利用融合AM的改进SAC深度强化学习算法在连续动作空间对模型进行求解。最后,对多能流调度结果进行仿真分析和对比实验,验证了文中方法的可行性及其相较于原SAC算法较高的决策准确性。
基金supported by the National Natural Science Foundation of China(22234005,21974070)the Natural Science Foundation of Jiangsu Province(BK20222015)。
文摘Atomically dispersed catalysts exhibit significant influence on facilitating the sluggish oxygen reduction reaction(ORR)kinetics with high atom economy,owing to remarkable attributes including nearly 100%atomic utilization and exceptional catalytic functionality.Furthermore,accurately controlling atomic physical properties including spin,charge,orbital,and lattice degrees of atomically dispersed catalysts can realize the optimized chemical properties including maximum atom utilization efficiency,homogenous active centers,and satisfactory catalytic performance,but remains elusive.Here,through physical and chemical insight,we review and systematically summarize the strategies to optimize atomically dispersed ORR catalysts including adjusting the atomic coordination environment,adjacent electronic orbital and site density,and the choice of dual-atom sites.Then the emphasis is on the fundamental understanding of the correlation between the physical property and the catalytic behavior for atomically dispersed catalysts.Finally,an overview of the existing challenges and prospects to illustrate the current obstacles and potential opportunities for the advancement of atomically dispersed catalysts in the realm of electrocatalytic reactions is offered.
基金supported by the National Natural Science Foundation of China(52272194)Liaoning Revitalization Talents Program(XLYC2007155)。
文摘Lithium metal batteries are regarded as prominent contenders to address the pressing needs owing to the high theoretical capacity.Toward the broader implementation,the primary obstacle lies in the intricate multi-electron,multi-step redox reaction associated with sluggish conversion kinetics,subsequently giving rise to a cascade of parasitic issues.In order to smooth reaction kinetics,catalysts are widely introduced to accelerate reaction rate via modulating the energy barrier.Over past decades,a large amount of research has been devoted to the catalyst design and catalytic mechanism exploration,and thus the great progress in electrochemical performance has been realized.Therefore,it is necessary to make a comprehensive review toward key progress in catalyst design and future development pathway.In this review,the basic mechanism of lithium metal batteries is provided along with corresponding advantages and existing challenges detailly described.The main catalysts employed to accelerate cathode reaction with emphasis on their catalytic mechanism are summarized as well.Finally,the rational design and innovative direction toward efficient catalysts are suggested for future application in metal-sulfur/gas battery and beyond.This review is expected to drive and benefit future research on rational catalyst design with multi-parameter synergistic impacts on the activity and stability of next-generation metal battery,thus opening new avenue for sustainable solution to climate change,energy and environmental issues,and the potential industrial economy.
基金supported by the National Natural Science Foundation of China(21905253,51973200,and 52122308)the Natural Science Foundation of Henan(202300410372)the National Supercomputing Center in Zhengzhou
文摘The rational design of metal single-atom catalysts(SACs)for electrochemical nitrogen reduction reaction(NRR)is challenging.Two-dimensional metal-organic frameworks(2DMOFs)is a unique class of promising SACs.Up to now,the roles of individual metals,coordination atoms,and their synergy effect on the electroanalytic performance remain unclear.Therefore,in this work,a series of 2DMOFs with different metals and coordinating atoms are systematically investigated as electrocatalysts for ammonia synthesis using density functional theory calculations.For a specific metal,a proper metal-intermediate atoms p-d orbital hybridization interaction strength is found to be a key indicator for their NRR catalytic activities.The hybridization interaction strength can be quantitatively described with the p-/d-band center energy difference(Δd-p),which is found to be a sufficient descriptor for both the p-d hybridization strength and the NRR performance.The maximum free energy change(ΔG_(max))andΔd-p have a volcanic relationship with OsC_(4)(Se)_(4)located at the apex of the volcanic curve,showing the best NRR performance.The asymmetrical coordination environment could regulate the band structure subtly in terms of band overlap and positions.This work may shed new light on the application of orbital engineering in electrocatalytic NRR activity and especially promotes the rational design for SACs.
基金supported by the National Natural Science Foundation of China(51872115,12234018 and 52101256)Beijing Synchrotron Radiation Facility(BSRF,4B9A)。
文摘Atom-level modulation of the coordination environment for single-atom catalysts(SACs)is considered as an effective strategy for elevating the catalytic performance.For the MNxsite,breaking the symmetrical geometry and charge distribution by introducing relatively weak electronegative atoms into the first/second shell is an efficient way,but it remains challenging for elucidating the underlying mechanism of interaction.Herein,a practical strategy was reported to rationally design single cobalt atoms coordinated with both phosphorus and nitrogen atoms in a hierarchically porous carbon derived from metal-organic frameworks.X-ray absorption spectrum reveals that atomically dispersed Co sites are coordinated with four N atoms in the first shell and varying numbers of P atoms in the second shell(denoted as Co-N/P-C).The prepared catalyst exhibits excellent oxygen reduction reaction(ORR)activity as well as zinc-air battery performance.The introduction of P atoms in the Co-SACs weakens the interaction between Co and N,significantly promoting the adsorption process of ^(*)OOH,resulting in the acceleration of reaction kinetics and reduction of thermodynamic barrier,responsible for the increased intrinsic activity.Our discovery provides insights into an ultimate design of single-atom catalysts with adjustable electrocatalytic activities for efficient electrochemical energy conversion.
