In general,metal carbides are synthesized via high-temperature-programmed solid-gas reactions using methane under an inert atmosphere.However,fabricating single-atom(SA)catalysts on such carbide supports typically inh...In general,metal carbides are synthesized via high-temperature-programmed solid-gas reactions using methane under an inert atmosphere.However,fabricating single-atom(SA)catalysts on such carbide supports typically inherits these demanding conditions,requiring multiple chemical reagents and prolonged processing.To overcome these synthetic limitations,we introduced a pulsed laser-driven strategy that integrates pulsed laser ablation and liquid-phase irradiation to construct atomically dispersed Pt sites on molybdenum carbide(Pt/MoC)nanospheres with tunable loading densities.These catalysts exhibit improved hydrogen evolution reaction(HER)activity in alkaline media,despite HER conventionally favoring acidic conditions.To enhance the hydrogen production efficiency of the electrolyzer while reducing energy consumption,we strategically replaced the conventional oxygen evolution reaction with the hydrazine oxidation reaction(HzOR)at the anode.Strong metal-support interactions between Pt atoms and MoC modulate the local electronic structure,thereby optimizing the adsorption energies of key intermediates for HzOR.In situ Raman spectroelectrochemistry and theoretical calculations elucidate the reaction mechanism,highlighting the role of Pt SA sites in lowering activation barriers for N2 and H2 evolution.The optimized Pt/MoC catalyst achieves enhanced HER performance in overall hydrazine splitting compared with conventional overall water splitting,maintaining structural integrity and outstanding stability over 100 h at 30 mA cm^(-2).This study establishes a pulsed laser-based strategy for atomic-engineered Pt/MoC as a promising platform for energy-effective and hydrazine-fueled hydrogen generation in alkaline conditions.展开更多
针对高层建筑给水系统水锤效应防控问题,该研究旨在保障供水安全并优化运维成本。基于特征线法(Method of Characteristics,MOC)与计算流体力学(Computatioinal Fluid Dynamics,CFD)构建多尺度耦合分析模型,创新性提出“源头控制-过程调...针对高层建筑给水系统水锤效应防控问题,该研究旨在保障供水安全并优化运维成本。基于特征线法(Method of Characteristics,MOC)与计算流体力学(Computatioinal Fluid Dynamics,CFD)构建多尺度耦合分析模型,创新性提出“源头控制-过程调压-末端消能”三级协同防护体系。通过工程案例验证表明:系统压力峰值衰减率达64%,压力振荡持续时间缩减45%,符合ASSE1010标准中压力波动控制要求。研究成果为高层建筑给水系统瞬态防护设计提供理论依据与技术方案,促进水锤防护技术向动态调控与智能监测方向发展。展开更多
基金supported by the Korea Basic Science Institute(National research Facilities and Equipment Center)grant funded by the Ministry of Education(No.2019R1A6C1010042,RS-2024-00434932,and RS-2025-12872968)by the Korea government(MSIT)(PG2025039-02)+3 种基金support from the National Research Foundation of Korea(NRF),(2022R1A2C2010686,RS-2025-02634080,RS-2021-NR060090,and RS-2024-00405324)the Core-Facility Center for Photochemistry&Nanomaterials,Gyeongsang National University,In-situ Cryo X-ray Absorption Spectrometer,IC-XAS(NFEC-2025-07-307201)supported by the Glocal University 30 Project Fund of Gyeongsang National University in 2025the Odisha State Higher Education Council,Department of Higher Education,Government of Odisha for financial support under MRI(23EM/PH/123).
文摘In general,metal carbides are synthesized via high-temperature-programmed solid-gas reactions using methane under an inert atmosphere.However,fabricating single-atom(SA)catalysts on such carbide supports typically inherits these demanding conditions,requiring multiple chemical reagents and prolonged processing.To overcome these synthetic limitations,we introduced a pulsed laser-driven strategy that integrates pulsed laser ablation and liquid-phase irradiation to construct atomically dispersed Pt sites on molybdenum carbide(Pt/MoC)nanospheres with tunable loading densities.These catalysts exhibit improved hydrogen evolution reaction(HER)activity in alkaline media,despite HER conventionally favoring acidic conditions.To enhance the hydrogen production efficiency of the electrolyzer while reducing energy consumption,we strategically replaced the conventional oxygen evolution reaction with the hydrazine oxidation reaction(HzOR)at the anode.Strong metal-support interactions between Pt atoms and MoC modulate the local electronic structure,thereby optimizing the adsorption energies of key intermediates for HzOR.In situ Raman spectroelectrochemistry and theoretical calculations elucidate the reaction mechanism,highlighting the role of Pt SA sites in lowering activation barriers for N2 and H2 evolution.The optimized Pt/MoC catalyst achieves enhanced HER performance in overall hydrazine splitting compared with conventional overall water splitting,maintaining structural integrity and outstanding stability over 100 h at 30 mA cm^(-2).This study establishes a pulsed laser-based strategy for atomic-engineered Pt/MoC as a promising platform for energy-effective and hydrazine-fueled hydrogen generation in alkaline conditions.
文摘针对高层建筑给水系统水锤效应防控问题,该研究旨在保障供水安全并优化运维成本。基于特征线法(Method of Characteristics,MOC)与计算流体力学(Computatioinal Fluid Dynamics,CFD)构建多尺度耦合分析模型,创新性提出“源头控制-过程调压-末端消能”三级协同防护体系。通过工程案例验证表明:系统压力峰值衰减率达64%,压力振荡持续时间缩减45%,符合ASSE1010标准中压力波动控制要求。研究成果为高层建筑给水系统瞬态防护设计提供理论依据与技术方案,促进水锤防护技术向动态调控与智能监测方向发展。
