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Wang H, Dekel DR, Abruña HD. Unraveling the Mechanism of Ammonia Electrooxidation by Coupled Differential Electrochemical Mass Spectrometry and Surface-Enhanced Infrared Absorption Spectroscopic Studies. J Am Chem Soc 2024; 146:15926-15940. [PMID: 38820130 DOI: 10.1021/jacs.4c02621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2024]
Abstract
Ammonia electrooxidation has received considerable attention in recent times due to its potential application in direct ammonia fuel cells, ammonia sensors, and denitrification of wastewater. In this work, we used differential electrochemical mass spectrometry (DEMS) coupled with attenuated total reflection-surface-enhanced infrared absorption (ATR-SEIRA) spectroscopy to study adsorbed species and solution products during the electrochemical ammonia oxidation reaction (AOR) on Pt in alkaline media, and to correlate the product distribution with the surface ad-species. Hydrazine electrooxidation, hydroxylamine electrooxidation/reduction, and nitrite electroreduction on Pt have also been studied to enhance the understanding of the AOR mechanism. NH3, NH2, NH, NO, and NO2 ad-species were identified on the Pt surface with ATR-SEIRA spectroscopy, while N2, N2O, and NO were detected with DEMS as products of the AOR. N2 is formed through the coupling of two NH ad-species and then subsequent further dehydrogenation, while the dimerization of HNOad leads to the formation of N2O. The NH-NH coupling is the rate-determining step (rds) at high potentials, while the first dehydrogenation step is the rds at low potentials. These new spectroscopic results about the AOR and insights could advance the search and design of more effective AOR catalysts.
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Affiliation(s)
- Hongsen Wang
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301, United States
| | - Dario R Dekel
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301, United States
- The Wolfson Department of Chemical Engineering, Technion─Israel Institute of Technology, Haifa 3200003, Israel
- The Nancy & Stephen Grand Technion Energy Program (GTEP), Technion─Israel Institute of Technology, Haifa 3200003, Israel
| | - Héctor D Abruña
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301, United States
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Zhang L, Liu Y, Wang J. Selective and effective oxidation of ammonium to dinitrogen in MgO/Na 2SO 3/K 2S 2O 8 system. CHEMOSPHERE 2023; 325:138401. [PMID: 36925013 DOI: 10.1016/j.chemosphere.2023.138401] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 03/07/2023] [Accepted: 03/12/2023] [Indexed: 06/18/2023]
Abstract
The oxidation of ammonium (NH4+) to dinitrogen (N2) with high selectivity and high efficiency is still a challenge. Herein, a novel sunlight induced persulfate (PS)-based AOPs process (MgO/Na2SO3/PS/hv) was proposed by introducing solid base (MgO) and hydrated electron (eaq-), to selectively oxidize NH4+ to N2, with high selectivity and high efficiency at a wide range of pH value. The deprotonation of NH4+ into NH3 by MgO and the generation of •OH and SO4-• by PS activation were responsible for the high efficiency of NH4+ oxidation. The buffering capacity provided by MgO to proton released from PS activation made the NH4+ oxidation possible at a wide pH range. The eaq- from the Na2SO3/hv process was the main active specie to reduce NO2-and NO3- (NOx-) into N2, responsible for high N2 selectivity of NH4+ oxidation. 100% NH4+ could be oxidized within 30 min, and N2 selectivity exceeded 96% at the initial pH range of 3-11 and the initial concentration of NH4+ of 30 mg N/L. This work could offer an efficient AOPs process for selective NH4+ oxidation, which is promising for the chemical denitrification of wastewater ….
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Affiliation(s)
- Le Zhang
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610066, China
| | - Yong Liu
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610066, China
| | - Jianlong Wang
- Laboratory of Environmental Technology, INET, Tsinghua University, Beijing, 100084, China.
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3
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Dou J, Funderburg J, Yang K, Liu J, Chacko D, Zhang K, Harvey AP, Haribal VP, Zhou SJ, Li F. Ce xZr 1–xO 2-Supported CrO x Catalysts for CO 2-Assisted Oxidative Dehydrogenation of Propane─Probing the Active Sites and Strategies for Enhanced Stability. ACS Catal 2022. [DOI: 10.1021/acscatal.2c05286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Jian Dou
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27606, United States
| | - Joey Funderburg
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27606, United States
| | - Kunran Yang
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27606, United States
| | - Junchen Liu
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27606, United States
| | - Dennis Chacko
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27606, United States
| | - Kui Zhang
- School of Engineering, Newcastle University, Tyne NE1 7RU, U.K
| | - Adam P. Harvey
- School of Engineering, Newcastle University, Tyne NE1 7RU, U.K
| | - Vasudev P. Haribal
- Susteon Inc., 5001 Weston Pkwy, Cary, North Carolina 27513, United States
| | - S. James. Zhou
- Susteon Inc., 5001 Weston Pkwy, Cary, North Carolina 27513, United States
| | - Fanxing Li
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27606, United States
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Xu L, Liu D, Liu W, Yang J, Huang J, Wang X, He Q. Ammonia Recovery from Wastewater as a Fuel: Effects of Supporting Electrolyte on Ammonium Permeation through a Cation-Exchange Membrane. ACS OMEGA 2022; 7:20634-20643. [PMID: 35755378 PMCID: PMC9219067 DOI: 10.1021/acsomega.2c00700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 04/20/2022] [Indexed: 06/15/2023]
Abstract
Electrodeionization (EDI) is used to recover ammonia from wastewater as a fuel, but how its performance for ammonia recovery is affected by the supporting electrolyte is not very clear. This study involved experimental tests and theoretical calculations on NH3 recovery, NH4 + permeation, and NH4 + and Na+ interacting with the functional groups in a cation exchange membrane (CEM) using Na2SO4 as the supporting electrolyte. The results demonstrated that a low concentration (≤0.250 mol L-1 of Na2SO4) was conducive to NH4 + permeation, while the a concentration (0.750 mol L-1 of Na2SO4) hindered NH4 + permeation. A maximum recovery efficiency of ammonia of 80.00%, a current efficiency of 70.10%, and an energy balance ratio of 0.66 were obtained at 0.250 mol L-1 of Na2SO4. Numerical results indicated that an increase in Na2SO4 concentration caused severe concentration polarization that resisted NH4 + migration in the CEM. The DFT results demonstrated that competitive adsorption of Na+ to the CEM hindered NH4 + migration. The weaker interacting force between NH4 + and the sulfonate functional group (-SOH3) in comparison to that between Na+ and -SOH3 might be related to the geometric and orientation effects, which generated an additional energy barrier for NH4 + transport. Therefore, this study suggests that the supporting electrolyte concentration should be matched with that of the desalted ions.
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Affiliation(s)
- Linji Xu
- Faculty
of Environment and Ecology, Chongqing University, Chongqing 400044, People’s Republic of China
| | - Dingyang Liu
- Chongqing
Key Laboratory of Heterogeneous Material Mechanics, College of Aerospace
Engineering, Chongqing University, Chongqing 400040, People’s Republic of China
| | - Wenzong Liu
- School
of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, People’s Republic of China
| | - Jixiang Yang
- Key
Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese
Academy of Sciences, Chongqing, 401174, People’s Republic
of China
| | - Jiansheng Huang
- School
of Chemistry and Chemical Engineering, Chongqing
University of Science and Technology, Chongqing 401331, People’s Republic of China
| | - Xinzhu Wang
- Chongqing
Key Laboratory of Heterogeneous Material Mechanics, College of Aerospace
Engineering, Chongqing University, Chongqing 400040, People’s Republic of China
| | - Qiang He
- Faculty
of Environment and Ecology, Chongqing University, Chongqing 400044, People’s Republic of China
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Estejab A, García Cárcamo RA, Getman RB. Influence of an electrified interface on the entropy and energy of solvation of methanol oxidation intermediates on platinum(111) under explicit solvation. Phys Chem Chem Phys 2022; 24:4251-4261. [PMID: 35107094 DOI: 10.1039/d1cp05358b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Liquid water and electric fields play significant roles in phenomena occurring at catalytic and electrocatalytic interfaces; however, how their interplay influences interfacial energetics remains uncertain. Electric fields control the orientations of water molecules, which we hypothesized would influence the solvation thermodynamics of surface species. To explore this hypothesis, we used multiscale simulations involving density functional theory and classical molecular dynamics. We computed the energies and entropies of solvation of surface species on Pt(111), specifically, adsorbed CH3OH, COH, and CO, which are intermediates in the pathway of methanol oxidation, in the presence of electric fields spanning -0.5 to +0.5 V Å-1. We found that both the energy and entropy of solvation depend on the strength and direction of the field, with the entropy of solvation being significantly impacted. Both the energy and entropy dependence on the field can be ascribed to water molecule orientations. Specifically, more positive fields orient water molecules so that they can more effectively hydrogen bond with surface species, which strengthens the energies of solvation. However, at more negative fields, competition with the surface species causes interfacial water molecules to reorient, which leads to disorder in the water structure and hence increased entropy.
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Affiliation(s)
- Ali Estejab
- Department of Chemical and Biomolecular Engineering, Clemson University, Clemson, SC 29634-0909, USA.
| | - Ricardo A García Cárcamo
- Department of Chemical and Biomolecular Engineering, Clemson University, Clemson, SC 29634-0909, USA.
| | - Rachel B Getman
- Department of Chemical and Biomolecular Engineering, Clemson University, Clemson, SC 29634-0909, USA.
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