Urea oxidation reaction(UOR) has been selected as substitution for oxygen evolution reaction ascribing to its low thermodynamic voltage as well as utilization of nickel as electrocatalyst.Herein,we report the formatio...Urea oxidation reaction(UOR) has been selected as substitution for oxygen evolution reaction ascribing to its low thermodynamic voltage as well as utilization of nickel as electrocatalyst.Herein,we report the formation of nickel single atoms(Ni-SAs) as exceptional bifunctional electrocatalyst toward UOR and hydrogen evolution reaction(HER) in urea-assisted water splitting.In UOR catalysis,Ni-SAs perform a superior catalytic performance than Ni-NP/NC and Pt/C ascribing to the formation of HOO-Ni-N_(4) structure evidenced by in-situ Raman spectroscopy,corresponding to a boosted mass activity by 175-fold at 1.4 V vs.RHE than Ni-NP/NC.Furthermore,Ni-SAs requires only 450 mV overpotential to obtain HER current density of 500 mA cm^(-2).136 mA cm^(-2) is achieved in urea-assisted water splitting at1.7 V for Ni-SAs,boosted by 5.7 times than Pt/C-IrO_(2) driven water splitting.展开更多
The utilization of single atoms(SAs)as trifunctional electrocatalyst for nitro-gen reduction,oxygen reduction,and oxygen evolution reactions(NRR,ORR,and OER)is still a formidable challenge.Herein,we devise one-pot syn...The utilization of single atoms(SAs)as trifunctional electrocatalyst for nitro-gen reduction,oxygen reduction,and oxygen evolution reactions(NRR,ORR,and OER)is still a formidable challenge.Herein,we devise one-pot synthesized palladium SAs stabilized on nitrogen-doped carbon palladium SA electrocat-alyst(Pd-SA/NC)as efficient trifunctional electrocatalyst for NRR,ORR,and OER.Pd-SA/NC performs a robust catalytic activity toward NRR with faradaic efficiency of 22.5%at-0.25 V versus reversible hydrogen electrode(RHE),and the relative Pd utilization efficiency is enhanced by 17-fold than Pd-NP/NC.In addition,the half-wave potential reaches 0.876 V versus RHE,amounting to a 58-time higher mass activity than commercial Pt/C.Moreover,the overpotential at 10 mA cm-2 is as low as 287 mV for Pd-SA/NC,outperforming the commer-cial IrO2 by 360 times in turnover frequency at 1.6 V versus RHE.Accordingly,the assembled rechargeable zinc-air battery(ZAB)achieves a maximum power den-sity of 170 mW cm-2,boosted by 2.3 times than Pt/C–IrO2.Two constructed ZABs efficiently power the NRR-OER system to electrochemically generate ammonia implying its superior trifunctionality.展开更多
基金supported by the National Natural Science Foundation of China(No.22209126)。
文摘Urea oxidation reaction(UOR) has been selected as substitution for oxygen evolution reaction ascribing to its low thermodynamic voltage as well as utilization of nickel as electrocatalyst.Herein,we report the formation of nickel single atoms(Ni-SAs) as exceptional bifunctional electrocatalyst toward UOR and hydrogen evolution reaction(HER) in urea-assisted water splitting.In UOR catalysis,Ni-SAs perform a superior catalytic performance than Ni-NP/NC and Pt/C ascribing to the formation of HOO-Ni-N_(4) structure evidenced by in-situ Raman spectroscopy,corresponding to a boosted mass activity by 175-fold at 1.4 V vs.RHE than Ni-NP/NC.Furthermore,Ni-SAs requires only 450 mV overpotential to obtain HER current density of 500 mA cm^(-2).136 mA cm^(-2) is achieved in urea-assisted water splitting at1.7 V for Ni-SAs,boosted by 5.7 times than Pt/C-IrO_(2) driven water splitting.
基金National Natural Science Foundation of China,Grant/Award Numbers:22209126,22279095Shccig-Qinling Program。
文摘The utilization of single atoms(SAs)as trifunctional electrocatalyst for nitro-gen reduction,oxygen reduction,and oxygen evolution reactions(NRR,ORR,and OER)is still a formidable challenge.Herein,we devise one-pot synthesized palladium SAs stabilized on nitrogen-doped carbon palladium SA electrocat-alyst(Pd-SA/NC)as efficient trifunctional electrocatalyst for NRR,ORR,and OER.Pd-SA/NC performs a robust catalytic activity toward NRR with faradaic efficiency of 22.5%at-0.25 V versus reversible hydrogen electrode(RHE),and the relative Pd utilization efficiency is enhanced by 17-fold than Pd-NP/NC.In addition,the half-wave potential reaches 0.876 V versus RHE,amounting to a 58-time higher mass activity than commercial Pt/C.Moreover,the overpotential at 10 mA cm-2 is as low as 287 mV for Pd-SA/NC,outperforming the commer-cial IrO2 by 360 times in turnover frequency at 1.6 V versus RHE.Accordingly,the assembled rechargeable zinc-air battery(ZAB)achieves a maximum power den-sity of 170 mW cm-2,boosted by 2.3 times than Pt/C–IrO2.Two constructed ZABs efficiently power the NRR-OER system to electrochemically generate ammonia implying its superior trifunctionality.
