N-doped hierarchical porous metal-free catalysts derived from covalent triazine frameworks for the efficient oxygen reduction reaction

2019 ◽  
Vol 9 (23) ◽  
pp. 6606-6612 ◽  
Author(s):  
Yaqi Cao ◽  
Yuanzhi Zhu ◽  
Xifan Chen ◽  
Bahreselam Sielu Abraha ◽  
Wenchao Peng ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Oxygen Reduction Reaction ◽  
Oxygen Diffusion ◽  
Active Sites ◽  
Porous Metal ◽  
Reduction Reaction ◽  
Metal Free ◽  
Hierarchical Porous ◽  
The Hierarchical Structure ◽  
Catalytic Active Sites

The hierarchical structure enhances oxygen diffusion, improves electron transfer, and exposes more catalytic active sites for the ORR.

NaCl protected synthesis of 3D hierarchical metal-free porous nitrogen-doped carbon catalysts for the oxygen reduction reaction in acidic electrolyte

2019 ◽  
Vol 55 (61) ◽  
pp. 9023-9026 ◽  
Author(s):  
Rui Wu ◽  
Xiaoju Wan ◽  
Jianghai Deng ◽  
Xun Huang ◽  
Siguo Chen ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
High Performance ◽  
Porous Metal ◽  
Reduction Reaction ◽  
Protective Agent ◽  
Metal Free ◽  
Hierarchical Porous ◽  
Carbon Catalysts ◽  
Nitrogen Doped Carbon

A high-performance 3D hierarchical porous metal-free N-doped carbon catalyst for oxygen reduction reaction in acidic medium was synthesized with ZnO as a mesoporous template and NaCl as both a macroporous template and a structure protective agent.

Self-assembly porous metal-free electrocatalysts templated from sulfur for efficient oxygen reduction reaction

2018 ◽  
Vol 462 ◽  
pp. 65-72 ◽  
Author(s):  
Qin Xiang ◽  
Sha Li ◽  
Xuefeng Zou ◽  
Yujie Qiang ◽  
Bingbing Hu ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Self Assembly ◽  
Porous Metal ◽  
Reduction Reaction ◽  
Metal Free

Facile potentiostatic preparation of functionalized polyterthiophene-anchored graphene oxide as a metal-free electrocatalyst for the oxygen reduction reaction

2015 ◽  
Vol 3 (10) ◽  
pp. 5426-5433 ◽  
Author(s):  
M. Halappa Naveen ◽  
Hui-Bog Noh ◽  
Md Shahriar Al Hossain ◽  
Jung Ho Kim ◽  
Yoon-Bo Shim
Keyword(s):  
Graphene Oxide ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Active Sites ◽  
Reduction Reaction ◽  
Metal Free

A new polyterthiophene-anchored GO electrocatalyst was prepared. The C–N bonds of the polymer served as active sites for the ORR catalyst.

scholarly journals Graphene/nitrogen-doped porous carbon sandwiches for the metal-free oxygen reduction reaction: conductivity versus active sites

2016 ◽  
Vol 4 (32) ◽  
pp. 12658-12666 ◽  
Author(s):  
M. Qiao ◽  
C. Tang ◽  
G. He ◽  
K. Qiu ◽  
R. Binions ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Porous Carbon ◽  
Active Sites ◽  
Electronic Conductivity ◽  
Hydrothermal Carbonization ◽  
Reduction Reaction ◽  
Active Nitrogen ◽  
Free Oxygen ◽  
Nitrogen Doped ◽  
Metal Free

Graphene/nitrogen-doped porous carbon sandwiches were prepared by hydrothermal carbonization. Once the electronic conductivity in the carbon–carbon hybrids reaches a certain value, the performance is controlled by the active nitrogen sites.

Template-free synthesis of polyacrylonitrile-derived porous carbon nanoballs on graphene for efficient oxygen reduction in zinc–air batteries

2021 ◽  
Vol 9 (15) ◽  
pp. 9644-9654
Author(s):  
Halima Begum ◽  
Mohammad Shamsuddin Ahmed ◽  
Seunghun Jung
Keyword(s):  
Fuel Cells ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Porous Carbon ◽  
Active Sites ◽  
Reduction Reaction ◽  
Metal Free ◽  
Template Free ◽  
Energy Conversion Devices ◽  
Zinc Air Batteries

Introducing abundant active sites and improving their activity are two critical considerations for designing metal-free nitrogenous electrocatalysts for the oxygen reduction reaction (ORR) in energy conversion devices such as metal–air batteries and fuel cells.

scholarly journals Fe-doped mayenite electride composite with 2D reduced Graphene Oxide: As a non-platinum based, highly durable electrocatalyst for Oxygen Reduction Reaction

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Karim Khan ◽  
Ayesha Khan Tareen ◽  
Muhammad Aslam ◽  
Sayed Ali Khan ◽  
Qasim khan ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Reduced Graphene Oxide ◽  
Precious Metal ◽  
Active Sites ◽  
Reduction Reaction ◽  
Metal Free ◽  
Reduced Graphene ◽  
Iron Based

AbstractSince the last decades, non-precious metal catalysts (NPMC), especially iron based electrocatalysts show sufficient activity, potentially applicant in oxygen reduction reaction (ORR), however they only withstand considerable current densities at low operating potentials. On the other hand iron based electrocatalysts are not stable at elevated cathode potentials, which is essential for high energy competence, and its remains difficult to deal. Therefore, via this research a simple approach is demonstrated that allows synthesis of nanosize Fe-doped mayenite electride, [Ca24Al28O64]4+·(e−)4 (can also write as, C12A7−xFex:e−, where doping level, x = 1) (thereafter, Fe-doped C12A7:e−), consist of abundantly available elements with gram level powder material production, based on simple citrate sol-gel method. The maximum achieved conductivity of this first time synthesized Fe-doped C12A7:e− composite materials was 249 S/cm. Consequently, Fe-doped C12A7:e− composite is cost-effective, more active and highly durable precious-metal free electrocatalyst, with 1.03 V onset potential, 0.89 V (RHE) half-wave potential, and ~5.9 mA/cm2 current density, which is higher than benchmark 20% Pt/C (5.65 mA/cm2, and 0.84 V). The Fe-doped C12A7:e− has also higher selectivity for desired 4e− pathway, and more stable than 20 wt% Pt/C electrode with higher immunity towards methanol poisoning. Fe-doped C12A7:e− loses was almost zero of its original activity after passing 11 h compared to the absence of methanol case, indicates that to introduce methanol has almost negligible consequence for ORR performance, which makes it highly desirable, precious-metal free electrocatalyst in ORR. This is primarily described due to coexistence of Fe-doped C12A7:e− related active sites with reduced graphene oxide (rGO) with pyridinic-nitrogen, and their strong coupling consequence along their porous morphology textures. These textures assist rapid diffusion of molecules to catalyst active sites quickly. In real system maximum power densities reached to 243 and 275 mW/cm2 for Pt/C and Fe-doped C12A7:e− composite, respectively.

scholarly journals Molten-Salt-Assisted Synthesis of Nitrogen-Doped Carbon Nanosheets Derived from Biomass Waste of Gingko Shells as Efficient Catalyst for Oxygen Reduction Reaction

Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2124
Author(s):  
Wei Hong ◽  
Xia Wang ◽  
Hongying Zheng ◽  
Rong Li ◽  
Rui Wu ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Specific Capacity ◽  
Reduction Reaction ◽  
Alkaline Media ◽  
Biomass Waste ◽  
Active Nitrogen ◽  
Nitrogen Doped ◽  
Metal Free ◽  
Hierarchical Porous

Developing superior efficient and durable oxygen reduction reaction (ORR) catalysts is critical for high-performance fuel cells and metal–air batteries. Herein, we successfully prepared a 3D, high-level nitrogen-doped, metal-free (N–pC) electrocatalyst employing urea as a single nitrogen source, NaCl as a fully sealed nanoreactor and gingko shells, a biomass waste, as carbon precursor. Due to the high content of active nitrogen groups, large surface area (1133.8 m2 g−1), and 3D hierarchical porous network structure, the as-prepared N–pC has better ORR electrocatalytic performance than the commercial Pt/C and most metal-free carbon materials in alkaline media. Additionally, when N–pC was used as a catalyst for an air electrode, the Zn–air battery (ZAB) had higher peak power density (223 mW cm−2), larger specific-capacity (755 mAh g−1) and better rate-capability than the commercial Pt/C-based one, displaying a good application prospect in metal-air batteries.

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