Ammonia has emerged as a promising energy carrier owing to its carbon neutral content and low expense in long-range transportation.Therefore,development of a specific pathway to release the energy stored in ammonia is...Ammonia has emerged as a promising energy carrier owing to its carbon neutral content and low expense in long-range transportation.Therefore,development of a specific pathway to release the energy stored in ammonia is therefore in urgent demand.Electrochemical oxidation provides a convenient and reliable route to attain efficient utilization of ammonia.Here,we report that the high entropy(Mn,Fe,Co,Ni,Cu)_(3)O_(4)oxides can achieve high electrocatalytic activity for ammonia oxidation reaction(AOR)in non-aqueous solutions.The AOR onset overpotential of(Mn,Fe,Co,Ni,Cu)_(3)O_(4)is 0.70 V,which is nearly 0.2 V lower than that of their most active single metal cation counterpart.The mass spectroscopy study reveals that(Mn,Fe,Co,Ni,Cu)_(3)O_(4)preferentially oxidizes ammonia to environmentally friendly diatomic nitrogen with a Faradic efficiency of over 85%.The Xray photoelectron spectroscopy(XPS)result indicates that the balancing metal d-band of Mn and Cu cations helps retain a longlasting electrocatalytic activity.Overall,this work introduces a new family of earth-abundant transition metal high entropy oxide electrocatalysts for AOR,thus heralding a new paradigm of catalyst design for enabling ammonia as an energy carrier.展开更多
基金supported by the Energy Research Seed Grant from Duke Energy Initiative,the National Science Foundation(Nos.CHE-1565657 and CHE-1954838)the Army Research Office(W911NFN-18-2-004)+2 种基金S.H.and P.N.are both supported by fellowships from Department of Chemistry at Duke UniversityThis work was performed in part at the Duke University Shared Materials Instrumentation Facility(SMIF),a member of the North Carolina Research Triangle Nanotechnology Network(RTNN)which is supported by the National Science Foundation(award number ECCS-2025064)as part of the National Nanotechnology Coordinated Infrastructure(NNCI).
文摘Ammonia has emerged as a promising energy carrier owing to its carbon neutral content and low expense in long-range transportation.Therefore,development of a specific pathway to release the energy stored in ammonia is therefore in urgent demand.Electrochemical oxidation provides a convenient and reliable route to attain efficient utilization of ammonia.Here,we report that the high entropy(Mn,Fe,Co,Ni,Cu)_(3)O_(4)oxides can achieve high electrocatalytic activity for ammonia oxidation reaction(AOR)in non-aqueous solutions.The AOR onset overpotential of(Mn,Fe,Co,Ni,Cu)_(3)O_(4)is 0.70 V,which is nearly 0.2 V lower than that of their most active single metal cation counterpart.The mass spectroscopy study reveals that(Mn,Fe,Co,Ni,Cu)_(3)O_(4)preferentially oxidizes ammonia to environmentally friendly diatomic nitrogen with a Faradic efficiency of over 85%.The Xray photoelectron spectroscopy(XPS)result indicates that the balancing metal d-band of Mn and Cu cations helps retain a longlasting electrocatalytic activity.Overall,this work introduces a new family of earth-abundant transition metal high entropy oxide electrocatalysts for AOR,thus heralding a new paradigm of catalyst design for enabling ammonia as an energy carrier.
