7664-41-7Relevant articles and documents
Modulating Single-Atom Palladium Sites with Copper for Enhanced Ambient Ammonia Electrosynthesis
Cheng, Hao,Han, Lili,Lin, Lili,Liu, Xijun,Luo, Jun,Ou, Pengfei,Ren, Zhouhong,Rui, Ning,Song, Jun,Sun, Jiaqiang,Xin, Huolin L.,Zhuo, Longchao
, p. 345 - 350 (2021)
The electrochemical reduction of N2 to NH3 is emerging as a promising alternative for sustainable and distributed production of NH3. However, the development has been impeded by difficulties in N2 adsorption, protonation of *NN, and inhibition of competing hydrogen evolution. To address the issues, we design a catalyst with diatomic Pd-Cu sites on N-doped carbon by modulation of single-atom Pd sites with Cu. The introduction of Cu not only shifts the partial density of states of Pd toward the Fermi level but also promotes the d-2π* coupling between Pd and adsorbed N2, leading to enhanced chemisorption and activated protonation of N2, and suppressed hydrogen evolution. As a result, the catalyst achieves a high Faradaic efficiency of 24.8±0.8 % and a desirable NH3 yield rate of 69.2±2.5 μg h?1 mgcat.?1, far outperforming the individual single-atom Pd catalyst. This work paves a pathway of engineering single-atom-based electrocatalysts for enhanced ammonia electrosynthesis.
Efficient electrochemical reduction of nitrate to nitrogen on tin cathode at very high cathodic potentials
Katsounaros,Ipsakis,Polatides,Kyriacou
, p. 1329 - 1338 (2006)
The electrochemical reduction of nitrate on tin cathode at very high cathodic potentials was studied in 0.1 M K2SO4, 0.05 M KNO3 electrolyte. A high rate of nitrate reduction (0.206 mmol min-1 cm-2) and a high selectivity (%S) of nitrogen (92%) was obtained at -2.9 V versus Ag/AgCl. The main by-products were ammonia (8%) and nitrite (2O and traces of NO were also detected. As the cathodic potential increases, the %S of nitrogen increases, while that of ammonia displays a maximum at -2.2 V. The %S of nitrite decreases from 65% at -1.8 V to A cathodic corrosion of tin was observed, which was more intensive in the absence of nitrate. At potentials more negative than -2.4 V, small amounts of tin hydride were detected.
Synthesis, Pharmacological, and Biological Evaluation of 2-Furoyl-Based MIF-1 Peptidomimetics and the Development of a General-Purpose Model for Allosteric Modulators (ALLOPTML)
Sampaio-Dias, Ivo E.,Rodríguez-Borges, José E.,Yá?ez-Pérez, Víctor,Arrasate, Sonia,Llorente, Javier,Brea, José M.,Bediaga, Harbil,Vin?, Dolores,Loza, Mariá Isabel,Caaman?, Olga,Garciá-Mera, Xerardo,González-Diáz, Humberto
, p. 203 - 215 (2021)
This work describes the synthesis and pharmacological evaluation of 2-furoyl-based Melanostatin (MIF-1) peptidomimetics as dopamine D2 modulating agents. Eight novel peptidomimetics were tested for their ability to enhance the maximal effect of tritiated N-propylapomorphine ([3H]-NPA) at D2 receptors (D2R). In this series, 2-furoyl-l-leucylglycinamide (6a) produced a statistically significant increase in the maximal [3H]-NPA response at 10 pM (11 ± 1%), comparable to the effect of MIF-1 (18 ± 9%) at the same concentration. This result supports previous evidence that the replacement of proline residue by heteroaromatic scaffolds are tolerated at the allosteric binding site of MIF-1. Biological assays performed for peptidomimetic 6a using cortex neurons from 19-day-old Wistar-Kyoto rat embryos suggest that 6a displays no neurotoxicity up to 100 μM. Overall, the pharmacological and toxicological profile and the structural simplicity of 6a makes this peptidomimetic a potential lead compound for further development and optimization, paving the way for the development of novel modulating agents of D2R suitable for the treatment of CNS-related diseases. Additionally, the pharmacological and biological data herein reported, along with >20a000 outcomes of preclinical assays, was used to seek a general model to predict the allosteric modulatory potential of molecular candidates for a myriad of target receptors, organisms, cell lines, and biological activity parameters based on perturbation theory (PT) ideas and machine learning (ML) techniques, abbreviated as ALLOPTML. By doing so, ALLOPTML shows high specificity Sp = 89.2/89.4%, sensitivity Sn = 71.3/72.2%, and accuracy Ac = 86.1%/86.4% in training/validation series, respectively. To the best of our knowledge, ALLOPTML is the first general-purpose chemoinformatic tool using a PTML-based model for the multioutput and multicondition prediction of allosteric compounds, which is expected to save both time and resources during the early drug discovery of allosteric modulators.
Cerium and tin oxides anchored onto reduced graphene oxide for selective catalytic reduction of NO with NH3 at low temperatures
Wang, Yanli,Kang, Ying,Ge, Meng,Zhang, Xiu,Zhan, Liang
, p. 36383 - 36391 (2018)
A series of cerium and tin oxides anchored on reduced graphene oxide (CeO2-SnOx/rGO) catalysts are synthesized using a hydrothermal method and their catalytic activities are investigated by selective catalytic reduction (SCR) of NO with NH3 in the temperature range of 120-280 °C. The results indicate that the CeO2-SnOx/rGO catalyst shows high SCR activity and high selectivity to N2 in the temperature range of 120-280 °C. The catalyst with a mass ratio of (Ce + Sn)/GO = 3.9 exhibits NO conversion of about 86% at 160 °C, above 97% NO conversion at temperatures of 200-280 °C and higher than 95% N2 selectivity at 120-280 °C. In addition, the catalyst presents a certain SO2 resistance. It is found that the highly dispersed CeO2 nanoparticles are deposited on the surface of rGO nanosheets, because of the incorporation of Sn4+ into the lattice of CeO2. The mesoporous structures of the CeO2-SnOx/rGO catalyst provides a large specific surface area and more active sites for facilitating the adsorption of reactant species, leading to high SCR activity. More importantly, the synergistic interaction between cerium and tin oxides is responsible for the excellent SCR activity, which results in a higher ratio of Ce3+/(Ce3+ + Ce4+), higher concentrations of surface chemisorbed oxygen and oxygen vacancies, more strong acid sites and stronger acid strength on the surface of the CeSn(3.9)/rGO catalyst.
Boosted electrocatalytic N2 reduction on fluorine-doped SnO2 mesoporous nanosheets
Liu, Ya-Ping,Li, Yu-Biao,Zhang, Hu,Chu, Ke
, p. 10424 - 10431 (2019)
The development of highly active and durable electrocatalysts toward the N2 reduction reaction (NRR) holds a key to ambient electrocatalytic NH3 synthesis. Herein, fluorine (F)-doped SnO2 mesoporous nanosheets on carbon cloth (F-SnO2/CC) were developed as an efficient NRR electrocatalyst. Benefiting from the combined structural advantages of mesoporous nanosheet structure and F-doping, the F-SnO2/CC exhibited high NRR activity with an NH3 yield of 19.3 μg h-1 mg-1 and a Faradaic efficiency of 8.6% at-0.45 V (vs RHE) in 0.1 M Na2SO4, comparable or even superior to those of most reported NRR electrocatalysts. Density functional theory calculations revealed that the F-doping could readily tailor the electronic structure of SnO2 to render it with improved conductivity and increased positive charge on active Sn sites, leading to the lowered reaction energy barriers and boosted NRR activity.
NO + H2 reaction on Pt(100). Steady state and oscillatory kinetics
Slinko, M.,Fink, T.,Loeher, T.,Madden, H. H.,Lombardo, S. J.,et al.
, p. 157 - 170 (1992)
The reaction of NO + H2 on Pt(100) was studied in the 10-6 mbar range between 300 and 800 K with mass spectrometry, work-function measurements, and video LEED. Both multiple steady states and kinetic oscillations were found. The principal reaction products were N2, H2O and NH3, and the activity and selectivity of the reaction were seen to depend on the partial pressure ratio pH(2)/pNO, on the surface temperature, and on the degree of surface reconstruction. Whereas the 1 × 1 surface of Pt was active for both N2 and NH3 formation, a well-annealed hex phase exhibited a low catalytic activity. The occurrence of defects during the 1 × 1 hex transition was shown to lead to enhanced N2 formation. At low pH(2)/pNO ratios, N2 formation was favored, while for large pH(2)/pNO ratios NH3 production was enhanced. Kinetic oscillations, as determined from variations in the N2, H2O and work-function signals, were found between 430 and 445 K.
Putting ammonia into a chemically opened fullerene
Whitener Jr., Keith E.,Frunze, Michael,Iwamatsu, Sho-Ichi,Murata, Shizuaki,Cross, R. James,Saunders, Martin
, p. 13996 - 13999 (2008)
We put ammonia into an open-cage fullerene with a 20-membered ring (1) as the orifice and examined the properties of the complex using NMR and MALDI-TOF mass spectroscopy. The proton NMR shows a broad resonance corresponding to endohedral NH3 at δH = -12.3 ppm relative to TMS. This resonance was seen to narrow when a 14N decoupling frequency was applied. MALDI spectroscopy confirmed the presence of both 1 (m/z = 1172) and 1 + NH3 (m/z = 1189), and integrated intensities of MALDI peak trains and NMR resonances indicate an incorporation fraction of 35-50% under our experimental conditions. NMR observations showed a diminished incorporation fraction after 6 months of storage at -10°C, which indicates that ammonia slowly escapes from the open-cage fullerene.
Catalytic Cleavage of the Amide Bond in Urea Using a Cobalt(III) Amino-Based Complex
Uprety, Bhawna,Arderne, Charmaine,Bernal, Ivan
, p. 5058 - 5067 (2018)
The urease mimetic activity of CoIII amine complexes with respect to cleavage of urea was explored using SCXRD and spectroscopic techniques. The reaction of [CoIII(tren)Cl2]Cl [tren = tris(2-aminoethyl)amine] with urea results in the formation of an isocyanato complex {[CoIII(tren)(NH3)(NCO)]Cl2} and ammonia, following the cleavage of the amide bond. The reaction progress and the subsequent formation of cleavage products were confirmed by SCXRD analysis of the reactants as well as the products obtained during the reaction. The reaction was found to be pH and temperature dependent, and the reaction conditions were optimized to maximize conversion. The reaction kinetics was followed spectroscopically (1H NMR and UV/Vis), following the decrease in urea concentration or the increase in pH succeeding ammonia formation. A detailed kinetic study revealed an overall second order rate law and kobs was found to be 3.89 × 10–4 m–1 s–1.
Turrentine, J. W.
, p. 803 (1911)
Vanadia directed synthesis of anatase TiO2 truncated bipyramids with preferential exposure of the reactive {001} facet
Shi, Quanquan,Li, Yong,Zhan, Ensheng,Ta, Na,Shen, Wenjie
, p. 3376 - 3382 (2015)
Anatase TiO2 truncated bipyramids that dominantly exposed the reactive {001} facet were hydrothermally synthesized using vanadia as the structure-directing agent. The exposed fraction of the {001} facet approached 53% upon adjusting the V/Ti mo
Grubb
, p. 600 (1923)
Browne, A. W.,Hoel, A. B.
, p. 2116 (1922)
NH3 formation from N2 and H2 mediated by molecular tri-iron complexes
Baabe, Dirk,Bontemps, Sébastien,Coppel, Yannick,Freytag, Matthias,Jones, Peter G.,Münster, Katharina,Maron, Laurent,Reiners, Matthias,Rosal, Iker del,Walter, Marc D.,Zaretzke, Marc-Kevin
, (2020)
Living systems carry out the reduction of N2 to ammonia (NH3) through a series of protonation and electron transfer steps under ambient conditions using the enzyme nitrogenase. In the chemical industry, the Haber–Bosch process hydrogenates N2 but requires high temperatures and pressures. Both processes rely on iron-based catalysts, but molecular iron complexes that promote the formation of NH3 on addition of H2 to N2 have remained difficult to devise. Here, we isolate the tri(iron)bis(nitrido) complex [(Cp′Fe)3(μ3-N)2] (in which Cp′ = η5-1,2,4-(Me3C)3C5H2), which is prepared by reduction of [Cp′Fe(μ-I)]2 under an N2 atmosphere and comprises three iron centres bridged by two μ3-nitrido ligands. In solution, this complex reacts with H2 at ambient temperature (22 °C) and low pressure (1 or 4 bar) to form NH3. In the solid state, it is converted into the tri(iron)bis(imido) species, [(Cp′Fe)3(μ3-NH)2], by addition of H2 (10 bar) through an unusual solid–gas, single-crystal-to-single-crystal transformation. In solution, [(Cp′Fe)3(μ3-NH)2] further reacts with H2 or H+ to form NH3. [Figure not available: see fulltext.].
Lee, J. Y.,Schwank, J.
, p. 207 - 215 (1986)
Adsorption and decomposition of hydrazine on Pd(100)
Dopheide,Schroeter,Zacharias
, p. 86 - 96 (1991)
The adsorption and decomposition of N2H4 on Pd(100) has been studied by measuring the sticking coefficient and by thermal desorption spectroscopy. Well-defined molecular beam dosing has been employed to limit the interaction of hydra
Relayed hyperpolarization from: Para -hydrogen improves the NMR detectability of alcohols
Rayner, Peter J.,Tickner, Ben. J.,Iali, Wissam,Fekete, Marianna,Robinson, Alastair D.,Duckett, Simon B.
, p. 7709 - 7717 (2019)
The detection of alcohols by magnetic resonance techniques is important for their characterization and the monitoring of chemical change. Hyperpolarization processes can make previously inpractical measurements, such as the determination of low concentration intermediates, possible. Here, we investigate the SABRE-Relay method in order to define its key characteristics and improve the resulting 1H NMR signal gains which subsequently approach 103 per proton. We identify optimal amine proton transfer agents for SABRE-Relay and show how catalyst structure influences the outcome. The breadth of the method is revealed by expansion to more complex alcohols and the polarization of heteronuclei.
The adsorption of gases on the surface of solid solutions and binary compounds of the GaSb-ZnTe system
Kirovskaya,Novgorodtseva,Vasina
, p. 1532 - 1536 (2007)
The adsorption of ammonia, carbon monoxide, and oxygen on solid solution and binary compound films of the GaSb-ZnTe system was studied. The mechanism of adsorption and rules governing adsorption processes depending on adsorption conditions and system comp
Iron Porphyrin-based Electrocatalytic Reduction of Nitrite to Ammonia
Barley, Mark H.,Takeuchi, Kenneth,Murphy, W. Rorer,Meyer, Thomas J.
, p. 507 - 508 (1985)
Electrocatalytic reduction of nitrite to ammonia has been demonstrated using a water-soluble iron porphyrin as catalyst.
Fixation of Molecular Nitrogen in Aqueous Solution Induced by Nitrogen Arc Plasma
Takasaki, Michiaki,Harada, Kaoru
, p. 437 - 440 (1987)
Argon Arc Plasma containing nitrogen gas (nitrogen arc plasma) was directly introduced into water, and a disproportionation reaction of molecular nitrogen took place in aqueous solution to form ammonia, nitrous acid, and nitric acid.The redox reaction of molecular nitrogen is interesting on the chemical evolutionary point of view as a possible route for the formation of ammonia under nonreducing conditions.
Ti3C2Tx (T = F, OH) MXene nanosheets: Conductive 2D catalysts for ambient electrohydrogenation of N2 to NH3
Zhao, Jinxiu,Zhang, Lei,Xie, Xiao-Ying,Li, Xianghong,Ma, Yongjun,Liu, Qian,Fang, Wei-Hai,Shi, Xifeng,Cui, Ganglong,Sun, Xuping
, p. 24031 - 24035 (2018)
The Haber-Bosch process for industrial-scale NH3 production suffers from high energy consumption and serious CO2 emission. Electrochemical N2 reduction is an attractive carbon-neutral alternative for NH3 synthesis but is severely restricted due to N2 activation needing efficient electrocatalysts for the N2 reduction reaction (NRR) under ambient conditions. Here, we report that Ti3C2Tx (T = F, OH) MXene nanosheets act as high-performance 2D NRR electrocatalysts for ambient N2-to-NH3 conversion with excellent selectivity. In 0.1 M HCl, such catalysts achieve a large NH3 yield of 20.4 g h-1 mgcat.-1 and a high faradic efficiency of 9.3% at -0.4 V vs. reversible hydrogen electrode, with high electrochemical and structural stability. Density functional theory calculations reveal that N2 chemisorbed on Ti3C2Tx experiences elongation/weakness of the NN triple bond facilitating its catalytic conversion to NH3 and the distal NRR mechanism is more favorable with the final reaction of ?NH2 to NH3 as the rate-limiting step.
Synthesis, characterization and reactivity of thiolate-bridged cobalt-iron and ruthenium-iron complexes
Guo, Chao,Su, Linan,Yang, Dawei,Wang, Baomin,Qu, Jingping
, p. 217 - 220 (2022)
Thiolate-bridged hetero-bimetallic complexes [Cp*M(MeCN)N2S2FeCl][PF6] (2, M = Ru; 3, M = Co, Cp* = η5-C5Me5, N2S2 = N,N'-dimethyl-3,6-diazanonane-1,8-dithiolate) were prepared by self-assembly of dimer [N2S2Fe]2 with mononuclear precursor [Cp*Ru(MeCN)3][PF6] or [Cp*Co(MeCN)3][PF6]2 in the presence of CHCl3 as a chloride donor. Complexes 2 and 3 exhibit obviously different redox behaviors investigated by cyclic voltammetry and spin density distributions supported by DFT calculations. Notably, iron-cobalt complex 3 possesses versatile reactivities that cannot be achieved for complex 2. In the presence of CoCp2, complex 3 can undergo one-electron reduction to generate a stable formally CoIIFeII complex [Cp*CoN2S2FeCl] (4). Besides, the terminal chloride on the iron center in 3 can be removed by dehalogenation agent AgPF6 or exchanged with azide to afford the corresponding complexes [Cp*Co(MeCN)N2S2Fe(MeCN)][PF6]2 (5) and [Cp*Co(MeCN)N2S2Fe(N3)][PF6] (6). In addition, complexes 2, 3 and 4 show distinct catalytic reactivity toward the disproportionation of hydrazine into ammonia. These results may be helpful to understand the vital role of the heterometal in some catalytic transformations promoted by heteromultinuclear complexes.
Triple C-H/N-H activation by O2 for molecular engineering: Heterobifunctionalization of the 19-electron redox catalyst Fe1Cp(arene)
Rigaut,Delville,Astruc
, p. 11132 - 11133 (1997)
-
Photocatalytic reduction of hydrazine to ammonia catalysed by [RuIII(edta)(H2O)]- complex in a Pt/TiO2 semiconductor particulate system
Chatterjee
, p. 1 - 3 (2000)
The illumination of aqueous suspensions of Pt/TiO2 semicondutor photocatalyst with [RuIII(edta)(H2O)]- led to the reduction of hydrazine to ammonia. Coordination of hydrazine to [RuIII(edta)(H2O)]- lowered the energy barrier significantly for the reduction of hydrazine. The rate controlling step of photocatalytic process was probably a surface chemical step (electron transfer) possibly coupled with adsorption of reactants and desorption of ammonia molecule. A working mechanism involving the formation of a [(RuIII(edta)(N2H5)] species (adsorbed onto TiO2 surface) that underwent two-electron transfer reduction followed by cleavage of the N-N bond of coordinated hydrazine was proposed.
Reactive Ionic Liquid Enables the Construction of 3D Rh Particles with Nanowire Subunits for Electrocatalytic Nitrogen Reduction
Chen, Tingting,Hao, Jingcheng,Li, Zhonghao,Liu, Shuai,Ying, Hao
, (2020)
Until now, the synthesis of Rh particles with unusual three-dimensional (3D) nanostructures is still challenging. A 3D nanostructure enables fast ion/molecule transport and possesses plenty of exposed active surface, and therefore it is of great interest to construct 3D Rh particles catalysts for the N2 reduction reaction (NRR). Herein, we proposed a reactive ionic liquid strategy for fabricating unusual 3D Rh particles with nanowires as the subunits. The ionic liquid n-octylammonium formate simultaneously worked as reaction medium, reductant and template for the successful construction of 3D Rh particles. The as-prepared 3D Rh particles demonstrated excellent activity for electrocatalytic N2 fixation in 0.1 M KOH electrolyte under ambient conditions with a high NH3 yield of 35.58 μg h?1 mgcat. ?1 at ?0.2 V versus reversible hydrogen electrode (RHE), surpassing most of the state-of-the-art noble metal catalysts. Our reactive ionic liquid strategy thus holds great promise for the rational construction of high-performance electrocatalysts toward NRR.
Ligand-field photolysis of [Mo(CN)8]4- in aqueous hydrazine: Trapped Mo(II) intermediate and catalytic disproportionation of hydrazine by cyano-ligated Mo(III,IV) complexes
Szklarzewicz, Janusz,Matoga, Dariusz,Klys, Agnieszka,Lasocha, Wieslaw
, p. 5464 - 5472 (2008)
The substitutional photolysis of K4[Mo(CN)8] ·2H2O in 98% N2H4·H2O has been investigated in detail. A molybdenum(II) intermediate, K 5[Mo(CN)7]·N2H4, is isolated in the primary stage of the reaction that involves the oxidation of N 2H4 to N2, as evidenced by the analysis of evolving gases. The powder X-ray crystal structure of K5[Mo(CN) 7]·N2H4 indicates the pentagonal bipiramidal geometry of the anion and the presence of N2H4 in proximity to the CN- ligands. The salt is characterized by means of EDS, IR, UV-vis, and EPR spectroscopy as well as cyclic voltammetry measurements. The secondary stages of photolysis, involving the catalytic decomposition of N2H4 into NH3 and N 2, lead to the formation of a molybdenum(IV) complex, [Mo(CN) 4O(NH3)]2-. The monitoring of the amounts of evolving gases combined with UV-vis and EPR spectroscopic measurements at various stages of photolysis indicate that the molybdenum(III,IV) couple is catalytically active. The scheme of the catalytic decomposition of hydrazine is presented and discussed.
A thiolate-bridged FeIVFeIV μ-nitrido complex and its hydrogenation reactivity toward ammonia formation
Chen, Hui,Mei, Tao,Qu, Jingping,Wang, Baomin,Wang, Junhu,Yang, Dawei,Ye, Shengfa,Zhang, Yixin,Zhao, Jinfeng,Zhou, Yuhan
, p. 46 - 52 (2021/12/27)
Iron nitrides are key intermediates in biological nitrogen fixation and the industrial Haber–Bosch process, used to form ammonia from dinitrogen. However, the proposed successive conversion of nitride to ammonia remains elusive. In this regard, the search for well-described multi-iron nitrido model complexes and investigations on controlling their reactivity towards ammonia formation have long been of great challenge and importance. Here we report a well-defined thiolate-bridged FeIVFeIV μ-nitrido complex featuring an uncommon bent Fe–N–Fe moiety. Remarkably, this complex shows excellent reactivity toward hydrogenation with H2 at ambient conditions, forming ammonia in high yield. Combined experimental and computational studies demonstrate that a thiolate-bridged FeIIIFeIII μ-amido complex is a key intermediate, which is generated through an unusual two-electron oxidation of H2. Moreover, ammonia production was also realized by treating this diiron μ-nitride with electrons and water as a proton source. [Figure not available: see fulltext.].
Rapid in situ synthesis of MgAl-LDH on η-Al2O3 for efficient hydrolysis of urea in wastewater
Guo, Chenyuan,Shen, Shuguang,Li, Meina,Wang, Ying,Li, Jing,Xing, Yuanquan,Wang, Cui,Pan, Huajie
, p. 54 - 62 (2021/01/19)
A rapid and efficient synthesis strategy of MgAl-LDH was proposed. MgAl-LDH with high specific surface area was synthesized in situ by using η-Al2O3 as carrier, and the synthesis time was greatly shortened by both increasing temperature and introducing ethanol as co-solvent. Besides, the growth process of MgAl-LDH on the surface of η-Al2O3 is also revealed. Under optimized conditions, the specific surface area of the MgAl-LDH is as high as 172.4 m2/g, the crystalline size is as small as 12.82 nm, and the basicity can reach 1.795 mmol/g. The urea wastewater was degraded from 8000 mg/L to 6.85 mg/L over the catalyst synthesized by the rapid method, and the catalyst still maintains high activity after four uses. Also, it was found that there is a good linear relationship between the urea removal rate and the basicity of MgAl-LDH.
Integrated selective nitrite reduction to ammonia with tetrahydroisoquinoline semi-dehydrogenation over a vacancy-rich Ni bifunctional electrode
Wang, Changhong,Zhou, Wei,Sun, Zhaojun,Wang, Yuting,Zhang, Bin,Yu, Yifu
supporting information, p. 239 - 243 (2021/01/15)
The development of efficient electrocatalysts for nitrite reduction to ammonia, especially integrated with a value-added anodic reaction, is important. Herein, Ni nanosheet arrays with Ni vacancies (Ni-NSA-VNi) were demonstrated to exhibit outstanding electrocatalytic performances toward selective nitrite reduction to ammonia (faradaic efficiency: 88.9%; selectivity: 77.2%) and semi-dehydrogenation of tetrahydroisoquinolines (faradaic efficiency: 95.5%; selectivity: 98.0%). The origin and quantitative analyses of ammonia were performed by 15N isotope labeling and 1H NMR experiments. The decrease in electronic cloud density induced by the Ni vacancies was found to improve the NO2- adsorption and NH3 desorption, leading to high nitrite-to-ammonia performance. In situ Raman results revealed the formation of NiII/NiIII active species for anodic semi-dehydrogenation of tetrahydroisoquinolines on Ni-NSA-VNi. Importantly, a Ni-NSA-VNi Ni-NSA-VNi bifunctional two-electrode electrolyzer was constructed to simultaneously produce ammonia and dihydroisoquinoline with robust stability and high selectivity.