Thermal Stability and Potential Cycling Durability of Nitrogen-Doped Graphene Modified by Metal-Organic Framework for Oxygen Reduction Reactions

Abstract

Here we report a nitrogen-doped graphene modified metal-organic framework (N-G/MOF) catalyst, a promising metal-free electrocatalyst exhibiting the potential to replace the noble metal catalyst from the electrochemical systems; such as fuel cells and metal-air batteries. The catalyst was synthesized with a planetary ball milling method, in which the precursors nitrogen-functionalized graphene (N-G) and ZIF-8 are ground at an optimized grinding speed and time. The N-G/MOF catalyst not only inherited large surface area from the ZIF-8 structure, but also had chemical interactions, resulting in an improved Oxygen Reduction Reaction (ORR) electrocatalyst. Thermogravimetric Analysis (TGA) curves revealed that the N-G/MOF catalyst still had some unreacted ZIF-8 particles, and the high catalytic activity of N-G particles decreased the decomposition temperature of ZIF-8 in the N-G/MOF catalyst. Also, we present the durability study of the N-G/MOF catalyst under a saturated nitrogen and oxygen environment in alkaline medium. Remarkably, the catalyst showed no change in the performance after 2000 cycles in the N2 environment, exhibiting strong resistance to the corrosion. In the O2 saturated electrolyte, the performance loss at lower overpotentials was as low compared to higher overpotentials. It is expected that the catalyst degradation mechanism during the potential cycling is due to the oxidative attack of the ORR intermediates.

Recent progress in metal–organic framework/graphene-derived materials for energy storage and conversion: design, preparation, and application

“…Metal-free N-doped porous carbon/rGO composites derived from ZIFs/GO by high temperature carbonization have been extensively used as electrocatalysts for the ORR and presented comparable performance to commercial Pt/C, due to the synergistic effect between porous NC and graphene with regard to structure and composition. 113,114,119,240 To further improve the ORR performance, embedding metal nanoparticles or single atoms into nitrogen-doped carbon (M-N-C, M ¼ Fe, Co, etc.) is a good choice.…”

Synthesis of MOFs/GO composite for corrosion resistance application on carbon steel

“…In addition, MOFs and GO have good corrosion inhibition performances, so compounding them can produce a synergistic corrosion inhibition effect and improve the corrosion resistance of the coating. 51 During the EIS tests, the impedance modulus of the low frequency region in the Bode diagram is oen used to evaluate the shielding performance of the coating. [52][53][54] Fig.…”

Synthesis and Performance of MOF-Based Non-Noble Metal Catalysts for the Oxygen Reduction Reaction in Proton-Exchange Membrane Fuel Cells: A Review

“…N-doped graphene-modified MOF catalyst was synthesized using a planetary ball milling method by grinding N-functionalized graphene (N-G, prepared by mixing graphene oxide and melamine for several hours) and ZIF-8 under optimized conditions without any heat treatment [ 61 ]. The obtained catalyst (N-G/MOF-350) presented both amorphous and crystalline structures inherited from ZIF-8 and N-G precursors, featuring a broad particle size distribution with an average of 955 nm and a fairly large BET surface area of 1039.8 m 2 g −1 , although the total pore volume remained low (≈0.42 cm 3 g −1 ).…”