Realizing nitrogen reduction reaction(NRR) to synthesis NH_(3) under mild conditions has gained extensive attention as a promising alternative way to the energy-and emission-intensive Haber-Bosch process.Among varieti...Realizing nitrogen reduction reaction(NRR) to synthesis NH_(3) under mild conditions has gained extensive attention as a promising alternative way to the energy-and emission-intensive Haber-Bosch process.Among varieties of potential strategies,photoelectrochemical(PEC) NRR exhibits many advantages including utilization of solar energy,water(H_(2)O) as the hydrogen source and ambient operation conditions.Herein,we have designed a solar-driven PEC-NRR system integrating high-efficiency Fe_(2)O_(3)-based photoanode and atomically dispersed cobalt(Co) cathode for ambient NH3 synthesis.Using such solar-driven PEC-NRR system,high-efficiency Fe_(2)O_(3)-based photoanode is responsible for H_(2)O/OH oxidatio n,and meanwhile the generated photoelectrons transfer to the single-atom Co cathode for the N_(2) reduction to NH_(3).As a result,this system can afford an NH_(3) yield rate of 1021.5 μg mg_(co)^(-1) h^(-1) and a faradic efficiency of 11.9% at an applied potential bias of 1.2 V(versus reversible hydrogen electrode) on photoanode in 0.2 mol/L NaOH electrolyte under simulated sunlight irradiation.展开更多
The oxygen evolution reaction(OER)is critical for sustainable energy technologies,including proton exchange membrane water electrolyzers(PEMWEs)and metal-air batteries.However,its implementation in acidic media remain...The oxygen evolution reaction(OER)is critical for sustainable energy technologies,including proton exchange membrane water electrolyzers(PEMWEs)and metal-air batteries.However,its implementation in acidic media remains constrained by sluggish kinetics,high energy barriers,and reliance on scarce noble-metal catalysts.Cobalt-based single-atom catalysts(Co-SACs)have emerged as a breakthrough solution,combining exceptional catalytic activity,stability,and atomic utilization efficiency.Its superior acidic OER performance stems from the electronic structure of low-spin Co^(3+)centers,which optimize t_(2g)–πorbital interactions with oxygen intermediates.This configuration promotes efficient surface reconstruction and thermodynamically favorable adsorption of OER species,accelerating reaction kinetics.Tailored coordination environments,engineered via supports like nitrogen-doped carbons,graphene,or metal oxides,can further modulate Co electronic and spin states,enhancing activity and durability.This review systematically analyzes advancements in Co-SAC design,elucidating correlations between atomic coordination,electronic properties,and catalytic mechanisms.Advanced synthesis methods and characterization tools are evaluated to discuss structure-activity relationships of Co-SAC.Finally,we address current challenges and future research directions that involve computational modeling,multi-metallic SAC architectures,and operando techniques to guide the rational design of high-performance Co-SACs.Addressing these challenges will accelerate the commercialization of PEMWEs for cost-effective green hydrogen production.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos.51872292 and 51672277)the CAS/SAFEA International Partnership Program for Creative Research Teams of Chinese Academy of Sciences,China。
文摘Realizing nitrogen reduction reaction(NRR) to synthesis NH_(3) under mild conditions has gained extensive attention as a promising alternative way to the energy-and emission-intensive Haber-Bosch process.Among varieties of potential strategies,photoelectrochemical(PEC) NRR exhibits many advantages including utilization of solar energy,water(H_(2)O) as the hydrogen source and ambient operation conditions.Herein,we have designed a solar-driven PEC-NRR system integrating high-efficiency Fe_(2)O_(3)-based photoanode and atomically dispersed cobalt(Co) cathode for ambient NH3 synthesis.Using such solar-driven PEC-NRR system,high-efficiency Fe_(2)O_(3)-based photoanode is responsible for H_(2)O/OH oxidatio n,and meanwhile the generated photoelectrons transfer to the single-atom Co cathode for the N_(2) reduction to NH_(3).As a result,this system can afford an NH_(3) yield rate of 1021.5 μg mg_(co)^(-1) h^(-1) and a faradic efficiency of 11.9% at an applied potential bias of 1.2 V(versus reversible hydrogen electrode) on photoanode in 0.2 mol/L NaOH electrolyte under simulated sunlight irradiation.
基金supported by the Beijing-Tianjin-Hebei Fundamental Research Cooperation Project(No.B2024202090)Sponsored by CNPC Innovation Found(No.2024DQ02-0311)We also thank the Haihe Laboratory of Sustainable Chemical Transformations(No.24HHWCSS00009)for financial support on this work.
文摘The oxygen evolution reaction(OER)is critical for sustainable energy technologies,including proton exchange membrane water electrolyzers(PEMWEs)and metal-air batteries.However,its implementation in acidic media remains constrained by sluggish kinetics,high energy barriers,and reliance on scarce noble-metal catalysts.Cobalt-based single-atom catalysts(Co-SACs)have emerged as a breakthrough solution,combining exceptional catalytic activity,stability,and atomic utilization efficiency.Its superior acidic OER performance stems from the electronic structure of low-spin Co^(3+)centers,which optimize t_(2g)–πorbital interactions with oxygen intermediates.This configuration promotes efficient surface reconstruction and thermodynamically favorable adsorption of OER species,accelerating reaction kinetics.Tailored coordination environments,engineered via supports like nitrogen-doped carbons,graphene,or metal oxides,can further modulate Co electronic and spin states,enhancing activity and durability.This review systematically analyzes advancements in Co-SAC design,elucidating correlations between atomic coordination,electronic properties,and catalytic mechanisms.Advanced synthesis methods and characterization tools are evaluated to discuss structure-activity relationships of Co-SAC.Finally,we address current challenges and future research directions that involve computational modeling,multi-metallic SAC architectures,and operando techniques to guide the rational design of high-performance Co-SACs.Addressing these challenges will accelerate the commercialization of PEMWEs for cost-effective green hydrogen production.
