DC Field | Value | Language |
---|---|---|
dc.contributor.advisor | 오지훈 | - |
dc.contributor.author | Suh, Jungwon | - |
dc.contributor.author | 서정원 | - |
dc.date.accessioned | 2024-07-30T19:31:12Z | - |
dc.date.available | 2024-07-30T19:31:12Z | - |
dc.date.issued | 2024 | - |
dc.identifier.uri | http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=1096736&flag=dissertation | en_US |
dc.identifier.uri | http://hdl.handle.net/10203/321518 | - |
dc.description | 학위논문(석사) - 한국과학기술원 : 신소재공학과, 2024.2,[iii, 35 p. :] | - |
dc.description.abstract | The electrochemical reduction of waste nitrate (NO3-) to produce ammonia (NH3) is a promising eco-friendly technology and an alternative to the energy-intensive Haber-Bosch process. However, achieving high energy efficiency is challenging due to the requirement of high reaction overpotential and limited selectivity. In this study, we demonstrate a Co-Cu Dual-Atom Catalyst (DAC) that exhibits high faradaic efficiency at low overpotential due to the synergistic effect between well-dispersed Co and Cu active sites. The Co-Cu DAC was synthesized using a straightforward ligand-mediated method involving the calcination of a mixture of metal precursors, ligands, and carbon black. The formation of a single-atom structure with Metal-N-C coordination was confirmed by FT-EXAFS, TEM, and XPS analysis. In the overall NO3-→NO2-→NH3 conversion pathway of the Co-Cu DAC, the rate-determining step (RDS) for the Co active sites and Cu active sites were located at NO3-→NO2- and NO2-→NH3, respectively. Electrochemical analysis revealed that the Cu active sites in the Co-Cu DAC preferentially catalyze the reduction of NO3- to NO2-, while the Co active sites preferentially catalyze the reduction of NO2- to NH3. The consequent synergistic effect from sequential favorable reactions at each active site allows the bypassing of the RDS, reducing the overall reaction energy barrier. Consequently, the Co-Cu DAC exhibited excellent electrocatalytic activity, achieving a high NH3 faradaic efficiency of 91.2% at -0.3 V vs. RHE. Furthermore, compared to Co SAC and Cu SAC, which comprised active sites of single metal species, the NH3 yield increased by 2.3 and 5.4 times, respectively, at -0.4 V vs. RHE. The dual-atom strategy presented in this study provides further designs for single-atom catalysts and demonstrates the potential for hetero-structured catalysts. | - |
dc.language | eng | - |
dc.publisher | 한국과학기술원 | - |
dc.subject | 암모니아▼a질산염▼a전기화학▼a이종 원자 촉매▼a단일 원자 촉매▼a활성 부위 상호작용 | - |
dc.subject | Ammonia▼aNitrate▼aElectrochemical▼aDual-atom catalyst▼aSingle-atom catalyst▼aActive site synergy | - |
dc.title | Analysis of electrochemical ammonia production properties of cobalt-copper dual-atom catalyst | - |
dc.title.alternative | 전기화학적 암모니아 생산을 위한 코발트-구리 이종 원자 촉매 특성 분석 | - |
dc.type | Thesis(Master) | - |
dc.identifier.CNRN | 325007 | - |
dc.description.department | 한국과학기술원 :신소재공학과, | - |
dc.contributor.alternativeauthor | Oh, Jihun | - |
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.