The development of high-performance and low-cost oxygen reduction and evolution catalysts that can be easily integrated into existing devices is crucial for the wide deployment of energy storage systems that utilize O...The development of high-performance and low-cost oxygen reduction and evolution catalysts that can be easily integrated into existing devices is crucial for the wide deployment of energy storage systems that utilize O2-H2O chemistries, such as regenerative fuel cells and metal-air batteries. Herein, we report an NHB-activated N-doped hierarchical carbon （NHC） catalyst synthesized via a scalable route, and demonstrate its device integration. The NHC catalyst exhibited good performance for both the oxygen reduction reaction （ORR） and the oxygen evolution reaction （OER）, as demonstrated by means of electrochemical studies and evaluation when integrated into the oxygen electrode of a regenerative fuel cell. The activities observed for both the ORR and the OER were comparable to those achieved by state-of-the-art Pt and Ir catalysts in alkaline environments. We have further identified the critical role of carbon defects as active sites for electrochemical activity through density functional theory calculations and high-resolution TEM visualization. This work highlights the potential of NHC to replace commercial precious metals in regenerative fuel cells and possibly metal-air batteries for cost-effective storage of intermittent renewable energy.展开更多
Developing a descriptor to understand the reactivity of a catalyst is critical in achieving the rational design of heterogeneous catalysts.Ideally,the descriptor should be simple,predictive,as well as applicable to di...Developing a descriptor to understand the reactivity of a catalyst is critical in achieving the rational design of heterogeneous catalysts.Ideally,the descriptor should be simple,predictive,as well as applicable to diverse types of reactions.This paper describes the development of a descriptor that could meet such ideal requirements based on its element-specific fundamental property,ionization energy.Our results indicated that ionization energies could be utilized to describe successfully the adsorption energies of oxygen(O*)and hydroxyl(OH*)groups on various materials.Moreover,we constructed a bond formation scheme to parse this phenomenon.展开更多
文摘The development of high-performance and low-cost oxygen reduction and evolution catalysts that can be easily integrated into existing devices is crucial for the wide deployment of energy storage systems that utilize O2-H2O chemistries, such as regenerative fuel cells and metal-air batteries. Herein, we report an NHB-activated N-doped hierarchical carbon （NHC） catalyst synthesized via a scalable route, and demonstrate its device integration. The NHC catalyst exhibited good performance for both the oxygen reduction reaction （ORR） and the oxygen evolution reaction （OER）, as demonstrated by means of electrochemical studies and evaluation when integrated into the oxygen electrode of a regenerative fuel cell. The activities observed for both the ORR and the OER were comparable to those achieved by state-of-the-art Pt and Ir catalysts in alkaline environments. We have further identified the critical role of carbon defects as active sites for electrochemical activity through density functional theory calculations and high-resolution TEM visualization. This work highlights the potential of NHC to replace commercial precious metals in regenerative fuel cells and possibly metal-air batteries for cost-effective storage of intermittent renewable energy.
基金supported from the National Natural Science Foundation of China(nos.21525626,21761132023,and 21676181)the Program of Introducing Talents of Discipline to Universities(no.B06006)。
文摘Developing a descriptor to understand the reactivity of a catalyst is critical in achieving the rational design of heterogeneous catalysts.Ideally,the descriptor should be simple,predictive,as well as applicable to diverse types of reactions.This paper describes the development of a descriptor that could meet such ideal requirements based on its element-specific fundamental property,ionization energy.Our results indicated that ionization energies could be utilized to describe successfully the adsorption energies of oxygen(O*)and hydroxyl(OH*)groups on various materials.Moreover,we constructed a bond formation scheme to parse this phenomenon.
