To contribute a solution for the global warming problem, the selective electrochemical reduction of CO to CO was studied in the gas phase using a [CO(g), Co-N-C cathode | Nafion-H | Pt/C anode, H/water] system without using carbonate solutions. The Co-N-C electrocatalysts were synthesized by partial pyrolysis of precursors in inert gas, which were prepared from various N-bidentate ligands, Co(NO), and Ketjenblack (KB). The most active electrocatalyst was Co-(4,4'-dimethyl-2,2'-bipyridine)/KB pyrolyzed at 673 K, denoted Co-4,4'-dmbpy/KB(673K). A high performance of CO formation (331 μmol h cm, 217 TOF h) at 0.020 A cm with 78% current efficiency was obtained at -0.75 V (SHE) and 273 K under strong acidic conditions of Nafion-H. Characterization studies using extended X-ray absorption fine structure (EXAFS), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy-energy-dispersive X-ray (TEM-EDX), X-ray diffraction (XRD), and temperature-programmed desorption with mass spectrometry (TPD-MS) indicated the active site as Co coordinated with four N atoms bonding the surface of KB, abbreviated Co-N-C structure. A model of the reduction mechanism of CO on the active site was proposed.
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http://dx.doi.org/10.1021/acsomega.0c01510 | DOI Listing |
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December 2024
School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an, 710049, China.
Achieving efficient and stable hydrogen evolution reactions in alkaline conditions is crucial for hydrogen production. In this study, a RuIr/CoNC-P catalyst featuring RuIr alloys alongside P-doping and CoNx sites is developed. RuIr alloying optimizes the electronic structure between Ru and Ir, promoting electron transfer from Ru to Ir.
View Article and Find Full Text PDFChemistry
October 2024
School of Chemical and Environmental Engineering, China University of Mining & Technology (Beijing), Beijing, 100083, P. R. China.
Bifunctional catalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are essential components of rechargeable zinc-air batteries. In this study, we synthesized a PrBaMnCoRuO (PBMCRO) perovskite composite with in situ exsolved CoRu nanoparticles and Co-N-C, functioning as an efficient bifunctional electrocatalyst for zinc-air batteries. The in situ exsolution of CoRu nanoparticles from the perovskite oxide was facilitated by the reducing action of 2-methylimidazole (2-MIM).
View Article and Find Full Text PDFLangmuir
August 2024
Key Laboratory of Advanced Catalytic Materials and Technology, Advanced Catalysis and Green Manufacturing Collaborative Innovation Center, Changzhou University, Changzhou, Jiangsu 213164, People's Republic of China.
It offers bright prospects to develop non-Pt group metal (non-PGM) electrocatalysts in the area of energy storage and conversion. Herein, we reported a simple spatial isolation strategy to synthesize Co-based electrocatalysts, using partially substituted Zn atoms in a ZnCo-ZIF precursor. The "fence" effect that originated from the partially substituted Zn atoms can yield a better isolation of Co atoms, achieving selective loading of Co species on nitrogen-doped porous carbon varying from nanoparticles to single atoms.
View Article and Find Full Text PDFNanoscale
July 2024
Department of Chemistry, National Institute of Technology Warangal, Hanumakonda-506004, Telangana, India.
As non-renewable resources are finite and cannot be utilized indefinitely, hydrogen (H) has emerged as a promising alternative for clean and sustainable energy. The cost-effective hydrogen production to meet large-scale commercial demand poses a significant challenge. Water electrolysis, powered by electricity derived from renewable resources, stands out as a viable route towards sustainable hydrogen production, with electrocatalysis playing a pivotal role in this process.
View Article and Find Full Text PDFACS Appl Mater Interfaces
June 2024
College of Materials and Chemical Engineering, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, China Three Gorges University, Yichang 443002, China.
Development of cheap, highly active, and durable nonprecious metal-based oxygen electrocatalysts is essential for metal-air battery technology, but achieving the balance of oxygen evolution reaction (OER)/oxygen reduction reaction (ORR) bifunctional performance and long-term durability is still a great challenge. Using a typical Co-N-C catalyst as a model, herein, we introduced ammonium chloride into nitrogen-doped carbon materials containing metal elements during the pyrolysis process (Co-N-C/AC), which not only increases the active area but also realizes the accurate customization of the active site (pyridine nitrogen and cobalt oxide species) so as to achieve the balance of the OER/ORR bifunctional sites. The synthesized Co-N-C/AC bifunctional catalyst with a three-dimensional porous structure exhibits a smaller potential gap of 0.
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