在“双碳”背景下,电制氨技术(renewable power to ammonia,RePtA)因能规模化消纳可再生能源与绿氢而受到广泛关注。然而,RePtA系统中可再生能源制氢量具有明显波动性,这对哈伯-博世合成氨工艺的稳定运行带来挑战。对此,提出了一种合成...在“双碳”背景下,电制氨技术(renewable power to ammonia,RePtA)因能规模化消纳可再生能源与绿氢而受到广泛关注。然而,RePtA系统中可再生能源制氢量具有明显波动性,这对哈伯-博世合成氨工艺的稳定运行带来挑战。对此,提出了一种合成氨离散多稳态柔性运行策略,并使用PSO-MILP算法建立了一个协同化工运行调度的容量配置两阶段优化模型,基于内蒙古某在建示范项目,对比分析了3种不同柔性方案的技术经济性能。研究表明:离散多稳态柔性策略相比传统稳态策略,经济性大幅度提高,年收益可增加6715万元;相比完全柔性策略,合成氨工艺的运行稳定性显著增强,生产负荷波动率降低了78.16%。该优化模型可以兼顾RePtA系统的投资经济性与运行安全性,其成果有望为实际生产运行提供一定指导。展开更多
Electrocatalytic nitrate reduction reaction (NO_(3)-RR) to ammonia under ambient conditions is expected to be a green process for ammonia synthesis and alleviate water pollution issues.We report a CuO nanoparticles in...Electrocatalytic nitrate reduction reaction (NO_(3)-RR) to ammonia under ambient conditions is expected to be a green process for ammonia synthesis and alleviate water pollution issues.We report a CuO nanoparticles incorporated on nitrogen-doped porous carbon (CuO@NC) catalyst for NO_(3)-RR.Part of Cu(Ⅱ) is reduced to Cu(Ⅰ) during the NO_(3)-RR process to construct Cu(Ⅰ)-Cu(Ⅱ) pairs,confirmed by in situ X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy.Density functional theory (DFT) calculations indicated that the formation of Cu(Ⅰ) could provide a reaction path with smaller energy barrier for NO_(3)-RR,while Cu(Ⅱ) effectively suppressed the competition of hydrogen evolution reaction (HER).As a result,CuO@NC catalyst achieved a Faradaic efficiency of 84.2% at -0.49 V versus reversible hydrogen electrode (RHE),and a NH_(3)yield rate of 17.2 mg h^(-1)mg^(-1)cat.at -0.79 V vs.RHE,higher than the HaberBosch process (<3.4 g h^(-1)g^(-1)cat.).This work may open a new avenue for effective NO_(3)-RR by modulating oxidation states.展开更多
Ammonia(NH_(3))is considered as one of the essential feedstocks in the fertilizer and chemical industries,serving as an ideal zero-carbon energy carrier.The ammonia synthesis process relies on Haber-Bosch process,prim...Ammonia(NH_(3))is considered as one of the essential feedstocks in the fertilizer and chemical industries,serving as an ideal zero-carbon energy carrier.The ammonia synthesis process relies on Haber-Bosch process,primarily involving the reaction between hydrogen(H_(2))and nitrogen(N_(2))at temperatures ranging from 400 to 500℃ and pressures exceeding 100 bar.A global total of 180 million metric tons of ammonia were produced annually in centralized industrial plants through the Haber-Bosch process,which consumes roughly 1% of the global energy supply and contributes over 1.3% of global carbon dioxide emissions[1].展开更多
Electrochemical nitrate(NO_(3)^(-))reduction offers a promising route for ammonia(NH_(3))synthesis from industrial wastewater using renewable energy.However,achieving selective and active NO_(3)^(-)to NH_(3)conversion...Electrochemical nitrate(NO_(3)^(-))reduction offers a promising route for ammonia(NH_(3))synthesis from industrial wastewater using renewable energy.However,achieving selective and active NO_(3)^(-)to NH_(3)conversion at low potentials remains challenging due to complex multi-electron transfer processes and competing reactions.Herein,we tackle this challenge by developing a cascade catalysis approach using synergistic active sites at Cu-Fe_(2)O_(3)interfaces,significantly reducing the NO_(3)^(-)to NH_(3)at a low onset potential to about+0.4 V_(RHE).Specifically,Cu optimizes^(*)NO_(3)adsorption,facilitating NO_(3)^(-)to nitrite(NO_(2)-)conversion,while adjacent Fe species in Fe_(2)O_(3)promote the subsequent NO_(2)-reduction to NH_(3)with favorable^(*)NO_(2)adsorption.Electrochemical operating experiments,in situ Raman spectroscopy,and in situ infrared spectroscopy consolidate this improved onset potential and reduction kinetics via cascade catalysis.An NH_(3)partial current density of~423 mA cm^(-2)and an NH_(3)Faradaic efficiency(FENH_(3))of 99.4%were achieved at-0.6 V_(RHE),with a maximum NH_(3)production rate of 2.71 mmol h^(-1)cm^(-2)at-0.8 V_(RHE).Remarkably,the half-cell energy efficiency exceeded 35%at-0.27 V_(RHE)(80%iR corrected),maintaining an FENH_(3)above 90%across a wide range of NO_(3)^(-)concentrations(0.05^(-1)mol L^(-1)).Using 15N isotopic tracing,we confirmed NO_(3)^(-)as the sole nitrogen source and attained a 98%NO_(3)^(-)removal efficiency.The catalyst exhibit stability over 106-h of continuous operation without noticeable degradation.This work highlights distinctive active sites in Cu-Fe_(2)O_(3)for promoting the cascade NO_(3)^(-)to NO_(2)^(-)and NO_(2)^(-)to NH_(3)electrolysis at industrial relevant current densities.展开更多
文摘在“双碳”背景下,电制氨技术(renewable power to ammonia,RePtA)因能规模化消纳可再生能源与绿氢而受到广泛关注。然而,RePtA系统中可再生能源制氢量具有明显波动性,这对哈伯-博世合成氨工艺的稳定运行带来挑战。对此,提出了一种合成氨离散多稳态柔性运行策略,并使用PSO-MILP算法建立了一个协同化工运行调度的容量配置两阶段优化模型,基于内蒙古某在建示范项目,对比分析了3种不同柔性方案的技术经济性能。研究表明:离散多稳态柔性策略相比传统稳态策略,经济性大幅度提高,年收益可增加6715万元;相比完全柔性策略,合成氨工艺的运行稳定性显著增强,生产负荷波动率降低了78.16%。该优化模型可以兼顾RePtA系统的投资经济性与运行安全性,其成果有望为实际生产运行提供一定指导。
基金National Natural Science Foundation of China (52371228, 52402045)fund of Key Laboratory of Advanced Materials of Ministry of Education(Advmat-2414)。
文摘Electrocatalytic nitrate reduction reaction (NO_(3)-RR) to ammonia under ambient conditions is expected to be a green process for ammonia synthesis and alleviate water pollution issues.We report a CuO nanoparticles incorporated on nitrogen-doped porous carbon (CuO@NC) catalyst for NO_(3)-RR.Part of Cu(Ⅱ) is reduced to Cu(Ⅰ) during the NO_(3)-RR process to construct Cu(Ⅰ)-Cu(Ⅱ) pairs,confirmed by in situ X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy.Density functional theory (DFT) calculations indicated that the formation of Cu(Ⅰ) could provide a reaction path with smaller energy barrier for NO_(3)-RR,while Cu(Ⅱ) effectively suppressed the competition of hydrogen evolution reaction (HER).As a result,CuO@NC catalyst achieved a Faradaic efficiency of 84.2% at -0.49 V versus reversible hydrogen electrode (RHE),and a NH_(3)yield rate of 17.2 mg h^(-1)mg^(-1)cat.at -0.79 V vs.RHE,higher than the HaberBosch process (<3.4 g h^(-1)g^(-1)cat.).This work may open a new avenue for effective NO_(3)-RR by modulating oxidation states.
基金supported by the National Natural Science Foundation of China(No.22105226)the Fundamental Research Funds for the Central Universities(23CX06019A and R20220132).
文摘Ammonia(NH_(3))is considered as one of the essential feedstocks in the fertilizer and chemical industries,serving as an ideal zero-carbon energy carrier.The ammonia synthesis process relies on Haber-Bosch process,primarily involving the reaction between hydrogen(H_(2))and nitrogen(N_(2))at temperatures ranging from 400 to 500℃ and pressures exceeding 100 bar.A global total of 180 million metric tons of ammonia were produced annually in centralized industrial plants through the Haber-Bosch process,which consumes roughly 1% of the global energy supply and contributes over 1.3% of global carbon dioxide emissions[1].
文摘Electrochemical nitrate(NO_(3)^(-))reduction offers a promising route for ammonia(NH_(3))synthesis from industrial wastewater using renewable energy.However,achieving selective and active NO_(3)^(-)to NH_(3)conversion at low potentials remains challenging due to complex multi-electron transfer processes and competing reactions.Herein,we tackle this challenge by developing a cascade catalysis approach using synergistic active sites at Cu-Fe_(2)O_(3)interfaces,significantly reducing the NO_(3)^(-)to NH_(3)at a low onset potential to about+0.4 V_(RHE).Specifically,Cu optimizes^(*)NO_(3)adsorption,facilitating NO_(3)^(-)to nitrite(NO_(2)-)conversion,while adjacent Fe species in Fe_(2)O_(3)promote the subsequent NO_(2)-reduction to NH_(3)with favorable^(*)NO_(2)adsorption.Electrochemical operating experiments,in situ Raman spectroscopy,and in situ infrared spectroscopy consolidate this improved onset potential and reduction kinetics via cascade catalysis.An NH_(3)partial current density of~423 mA cm^(-2)and an NH_(3)Faradaic efficiency(FENH_(3))of 99.4%were achieved at-0.6 V_(RHE),with a maximum NH_(3)production rate of 2.71 mmol h^(-1)cm^(-2)at-0.8 V_(RHE).Remarkably,the half-cell energy efficiency exceeded 35%at-0.27 V_(RHE)(80%iR corrected),maintaining an FENH_(3)above 90%across a wide range of NO_(3)^(-)concentrations(0.05^(-1)mol L^(-1)).Using 15N isotopic tracing,we confirmed NO_(3)^(-)as the sole nitrogen source and attained a 98%NO_(3)^(-)removal efficiency.The catalyst exhibit stability over 106-h of continuous operation without noticeable degradation.This work highlights distinctive active sites in Cu-Fe_(2)O_(3)for promoting the cascade NO_(3)^(-)to NO_(2)^(-)and NO_(2)^(-)to NH_(3)electrolysis at industrial relevant current densities.
