GDYNRR · Site-Specific Heteroatoms Doped Graphdiyne as Metal-Free Electrocatalysts for Nitrogen Reduction
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2021-08-01 → 2023-07-31
- EU contribution
- €191,149
- Participants
- 1
- Scheme
- MSCA-IF
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Results in brief
Site-Specific Heteroatoms Doped Graphdiyne as Metal-Free Electrocatalysts for Nitrogen Reduction
Ammonia is an important energy carrier and fertilizer feedstock for many industries and household chemicals. Currently, the large-scale production of ammonia is predominantly achieved by the energy- and capital-intensive Haber−Bosch process, which consumes 1% of the total energy production and results in 1.4% of the global CO2 emissions. Electrocatalytic ammonia production by using N-containing species has recently attracted great interests owing to the mild conditions and high compatibility with renewable electricity.[3] Compared to N2 with high dissociation energy (945 kJ mol-1) and low water solubility (Henry’s constant 0.62 mM bar-1 at 25 °C), nitrate (NO3-) is considered an attractive nitrogen precursor for NH3 electrosynthesis because of its low dissociation energy of the N=O bond (204 kJ mol-1), high water solubility (3.8 M at 25 °C as KNO3) and wide distribution as pollutant in wastewater. As the conversion of NO3−-to-NH3 involves a complex nine-proton coupled eight-electron transfer and multiple reaction pathways, the precise design of selective catalysts towards NH3 is considerably challenging. Noble-metal based catalysts especially ruthenium oxides/alloys have shown great promise in nitrate reduction (NO3RR), but the low abundance and high price severely restrict their large-scale application. Copper-based materials have recently appeared at the forefront of NO3RR due to the high abundance, strong adsorption of NO3− and favorable conversion from NO3−-to-NO2−.Nevertheless, the sequential hydrogenation process of NO2- under the assistance of Cu is poor due to the weak adsorption of active atom hydrogen (H*), which leads to a low selectivity and activity towards NH3. Therefore, developing novel Cu-based catalysts which couple the favorable conversion of nitrate to nitrite and the facilitation of subsequent hydrogenation is highly necessary. The overall objective of this project is to develop novel Cu-based catalysts which couple the favorable conversion of nitrate to nitrite and the facilitation of subsequent hydrogenation for high activity and selectivity towards NH3.In addition, the catalysts will be integrated in a functional device to test the performance under industrial relevant conditions.
Data: CORDIS, © European Union
Project objective
Eletrocatalytic nitrogen reduction reaction (NRR) has rencetly emerged as a sustainable alternative for ammonia production. However, the metal-based electrocatalysts for NRR suffer from low efficienciess due to the competing hydrogen evolution reaction. Heteroatoms doped carbon based metal-free catalysts feature weak integration with hydrogen, making them potential candidates for NRR. The NRR activity depends closely on the the form of doped atoms. The pyridinic N atoms and BC3 structure are demonstrated as the most active sites for ammonia synthesis. However, for widely researched carbon materials, it is difficult to selectively dope a sufficient amount of site-specific pyridinic N or BC3 atoms. As a lamellar carbon allotrope, graphdiyne (GDY), constituted by sp- and sp2- carbon atoms, is a great breakthrough. The high energy of sp-hybridization of acetylenic linkages enables the arbitrary angle rotation of π/π* perpendicular to the axis, endowing it a possibility to point towards N2. Another important feature of GDY is that it can be synthesized in solution via bottom-up method. A controllable heteroatoms doping method using a monomer design strategy, provides an ideal solution to achieve the site-specific doping. However, the attempt to design site-specific pyridinic N or BC3 atoms doped GDYs for electrocatalytic NRR has never been reported.The objective of this project is to selectively dope the site-specific pyridinic N and BC3 atoms into GDY to achieve the high performance and selectivity towards NRR. The influence of the pyridinic N and BC3 structure on the properties of GDY will be studied. Afterwards, the prepared site-specific heteroatoms doped GDYs will be used as electrocatalysts for NRR. Owing to the exact doping structure, the catalytic mechanisms for NRR will be recognized. At last, the optimal heteroatoms doped GDY electrode will be integrated in a functional N2 reduction device to demonstrate the overall N2 reduction in practical conditions.
Original text from CORDIS.
Participants
- ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE · LausanneCoordinatorSwitzerland
Links
Data: CORDIS, © European Union