1. Metal Organic Framework-Modified Graphene-based Catalyst for Oxygen Reduction Reaction
Shiqiang Zhuang*, Bharath Babu Nunna*, Eon Soo Lee (PI)
*New Jersey Institute of Technology, Mechanical Engineering
Conclusion
Project Objectives and Goals
Synthesis of New Graphene-based Catalyst— N-G/MOF
Current Density
(N-G VS. N-G/MOF VS. 10wt% Pt/C catalyst)
To discover and synthesize new graphene-based catalysts from graphene, nitrogen and metal organic framework material (MOF) by nanoscale high energy wet ball milling approach for oxygen reduction reaction (ORR) applications.
The synthesis reaction mechanism will be studied by understanding the changes of chemical properties, such as elemental composition and chemical bonding composition, during the reaction process.
To investigate the impact of experimental conditions, such as grinding speed, grinding time, jar conditions, environmental conditions, and grinding media condiitons on the properties of new graphene-based catalyst through physical, chemical, and electrochemical characterizations.
Synthesis process of the new N-G/MOF catalyst
Current Density J (mA/cm2)
5.0
N-G/MOF
N-G
4.5
Experimental Setup
10 wt% Pt/C
4.0
3.5
3.0
Potential/V
The N-G and N-G/MOF nanoparticles are successfully synthesized by nanoscale high energy wet ball milling. The N-G/MOF samples have 3D porous structure with high surface area.
Adding MOF as a reactant to react with N-G made significant changes on the structural properties and electrochemical properties of N-G. The current density of the new N-G/MOF catalyst reaches to 5.0 mA/cm2, which is already higher than the limiting current density of 10wt% Pt/C catalyst (4.5 mA/cm2).
A schematic representation of the nanoscale high energy wet ball milling approach to synthesize N-G in single step under room temperature.
Background
Experimental Conditions:
Reactants: Graphene Oxide, Melamine (mass ratio=1:6)
Grinding Jar: 12 mL
Grinding Speed: 200~650 RPM
Grinding Time: 24 hours
Grinding Environment: water
Grinding Media: Zirconia
Oxygen reduction reaction (ORR) and catalysts
Future Studies
The study of processing control : the influence of grinding speed, grinding time, etc. on the properties of N-G/MOF.
The study of the synthesis reaction mechanism of N-G/MOF by high energy wet ball milling method.
N-G/MOF catalysts are synthesized with N-G and MOF as reactants by nanoscale high energy wet ball milling approach.
N-G/MOF
Characterization of The New N-G/MOF Catalyst
(Yao Nie, Li Li* and Zidong Wei*, Recent advancements in Pt and Pt-free catalysts for oxygen reduction reaction, Chem. Soc. Rev. 2015, 44, DOI: /c4cs00484a)
Graphene-based catalyst
—Nitrogen-doped graphene (N-G)
Physical Characterization of The New N-G/MOF Catalyst
N-G
Particle size
~300 nm
MOF (ZIF-8)
Particle size
~500 nm
SEM image of a N-G/MOF(350 RPM) sample ~400 nm
TEM image of the N-G/MOF(350 RPM) sample
Advantages of Nitrogen doped graphene (N-G) catalysts:
Less cost than precious metal catalyst;
High oxygen reduction reaction (ORR) reactivity;
High surface area;
High electrical conductivity;
High chemical stability. +
Acknowledgment
Electrochemical Characterization of The New N-G/MOF Catalyst
Addition reactant for new graphene based catalyst
—Metal Organic Framework (MOF)
Authors like to thank NSF for funding this research under grant CMMI IIP I-Corps Site, program manager Anita J. LaSalle.
Research carried out (in whole or in part) at the Center for Functional Nanomaterials, Brookhaven National Laboratory, which is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. DE-SC
Rotating Ring Disk Electrode (RRDE) system Setup
RRDE Mechanism
Publications
Shiqiang Zhuang, Bharath Babu Nunna, Eon Soo Lee, Metal Organic Framework-Modified Nitrogen-Doped Graphene Catalysts for Oxygen Reduction Reaction, ECS Journal of Solid State Science and Technology, Submitted. (Mar 2017)
Shiqiang Zhuang, Bharath Babu Nunna, Jorge Anibal Boscoboinik, Eon Soo Lee, Nitrogen-Doped Graphene Catalysts: High Energy Wet Ball Milling Synthesis and Characterizations of Functional Groups and Particle Size Variation with Time and Speed, Int. J. Energy Res., Submitted. (Mar 2017)
S. Zhuang, E.S.Lee, Synthesis of nitrogen-doped graphene catalyst by high energy wet ball milling for electrochemical systems, Int. J. Energy Res. (7/12/2016), DOI:  /er.3595.
(d)
Main advantages of MOF:
Much larger specific surface area than N-Gs;
3-D micro-porous structure with high porosity;
High structural and thermal stability.