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1.
Nature ; 599(7884): 234-238, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34759363

RESUMO

Propane dehydrogenation (PDH) to propene is an important alternative to oil-based cracking processes, to produce this industrially important platform chemical1,2. The commercial PDH technologies utilizing Cr-containing (refs. 3,4) or Pt-containing (refs. 5-8) catalysts suffer from the toxicity of Cr(VI) compounds or the need to use ecologically harmful chlorine for catalyst regeneration9. Here, we introduce a method for preparation of environmentally compatible supported catalysts based on commercial ZnO. This metal oxide and a support (zeolite or common metal oxide) are used as a physical mixture or in the form of two layers with ZnO as the upstream layer. Supported ZnOx species are in situ formed through a reaction of support OH groups with Zn atoms generated from ZnO upon reductive treatment above 550 °C. Using different complementary characterization methods, we identify the decisive role of defective OH groups for the formation of active ZnOx species. For benchmarking purposes, the developed ZnO-silicalite-1 and an analogue of commercial K-CrOx/Al2O3 were tested in the same setup under industrially relevant conditions at close propane conversion over about 400 h on propane stream. The developed catalyst reveals about three times higher propene productivity at similar propene selectivity.

2.
Angew Chem Int Ed Engl ; 63(14): e202319192, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38271543

RESUMO

Improving the selectivity in the oxidative coupling of methane to ethane/ethylene poses a significant challenge for commercialization. The required improvements are hampered by the uncertainties associated with the reaction mechanism due to its complexity. Herein, we report about 90 % selectivity to the target products at 11 % methane conversion over Gd2O3-based catalysts at 700 °C using N2O as the oxidant. Sophisticated kinetic studies have suggested the nature of adsorbed oxygen species and their binding strength as key parameters for undesired methane oxidation to carbon oxides. These descriptors can be controlled by a metal oxide promoter for Gd2O3.

4.
Angew Chem Int Ed Engl ; 62(49): e202310062, 2023 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-37702304

RESUMO

Knowing the structure of catalytically active species/phases and providing methods for their purposeful generation are two prerequisites for the design of catalysts with desired performance. Herein, we introduce a simple method for precise preparation of supported/bulk catalysts. It utilizes the ability of metal oxides to dissolve and to simultaneously precipitate during their treatment in an aqueous ammonia solution. Applying this method for a conventional VOx -Al2 O3 catalyst, the concentration of coordinatively unsaturated Al sites was tuned simply by changing the pH value of the solution. These sites affect the strength of V-O-Al bonds of isolated VOx species and thus the reducibility of the latter. This method is also applicable for controlling the reducibility of bulk catalysts as demonstrated for a CeO2 -ZrO2 -Al2 O3 system. The application potential of the developed catalysts was confirmed in the oxidative dehydrogenation of ethylbenzene to styrene with CO2 and in the non-oxidative propane dehydrogenation to propene. Our approach is extendable to the preparation of any metal oxide catalysts dissolvable in an ammonia solution.

5.
Chem Soc Rev ; 50(1): 473-527, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33205797

RESUMO

Conversion of propane or butanes from natural/shale gas into propene or butenes, which are indispensable for the synthesis of commodity chemicals, is an important environmentally friendly alternative to oil-based cracking processes. Herein, we critically analyse recent developments in the non-oxidative, oxidative, and CO2-mediated dehydrogenation of propane and isobutane to the corresponding olefins over metal oxide catalysts. Particular attention is paid to (i) comparing the developed catalysts in terms of their application potential, (ii) structure-activity-selectivity relationships for tailored catalyst design, and (iii) reaction-engineering aspects for improving product selectivity and overall process efficiency. On this basis, possible directions for further research aimed at the development of inexpensive and environmentally friendly catalysts with industrially relevant performance were identified. In addition, we provide general information regarding catalyst preparation and characterization as well as some recommendations for carrying out non-oxidative and CO2-mediated dehydrogenation reactions to ensure unambiguous comparison of catalysts developed in different studies.

6.
Angew Chem Int Ed Engl ; 61(19): e202200772, 2022 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-35148454

RESUMO

The production of nitrous oxide, N2 O, via NH3 oxidation is not on a practical scale due to the lack of a suitable catalyst. Instead, it is produced via thermal decomposition of NH4 NO3 , rendering N2 O too costly and limiting its prospective uses. Herein, we report CeO2 -supported Au nanoparticles (2-3 nm) as a highly selective catalyst for low-temperature NH3 oxidation to N2 O, exhibiting two orders of magnitude higher space-time yield than the state-of-the-art Mn-Bi/α-Al2 O3 and remarkable stability over 70 h on stream. The reaction proceeds via a Mars-van Krevelen mechanism, with the density of interfacial Auδ+ species and the oxygen storage capacity of CeO2 identified as the key performance descriptors. The latter could be enhanced by cobalt doping, improving the catalytic activity and setting a new benchmark for N2 O productivity. These findings establish NH3 oxidation as an efficient process for N2 O manufacture and facilitate its broader utilization in selective oxidations.

7.
Angew Chem Int Ed Engl ; 61(22): e202116517, 2022 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-35244964

RESUMO

Alkali metal promoters have been widely employed for preparation of heterogeneous catalysts used in many industrially important reactions. However, the fundamentals of their effects are usually difficult to access. Herein, we unravel mechanistic and kinetic aspects of the role of alkali metals in CO2 hydrogenation over Fe-based catalysts through state-of-the-art characterization techniques, spatially resolved steady-state and transient kinetic analyses. The promoters affect electronic properties of iron in iron carbides. These carbide characteristics determine catalyst ability to activate H2 , CO and CO2 . The Allen scale electronegativity of alkali metal promoter was successfully correlated with the rates of CO2 hydrogenation to higher hydrocarbons and CH4 as well as with the rate constants of individual steps of CO or CO2 activation. The derived knowledge can be valuable for designing and preparing catalysts applied in other reactions where such promoters are also used.

8.
Environ Sci Technol ; 54(19): 11753-11761, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-32790302

RESUMO

The impact of formaldehyde (HCHO, formed in vehicle exhaust gases by incomplete combustion of fuel) on the performance of a commercial V2O5-WO3/TiO2 catalyst in NH3-SCR of NOx under dry conditions has been analyzed in detail by catalytic tests, in situ FTIR and transient studies using temporal analysis of products (TAP). HCHO reacts preferentially with NH3 to a formamide (HCONH2) surface intermediate. This deprives NH3 partly from its desired role as a reducing agent in the SCR and diminishes NO conversion and N2 selectivity. Between 250 and 400 °C, HCONH2 decomposes by dehydration (major pathway) and decarbonylation (minor pathway) to liberate toxic HCN and CO, respectively. HCN was proven to be oxidized by lattice oxygen of the catalyst to CO2 and NO, which enters the NH3-SCR reaction.


Assuntos
Amônia , Titânio , Catálise , Formaldeído
9.
Psychol Med ; 49(1): 140-148, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29554995

RESUMO

BACKGROUND: Schizophrenia and autism spectrum disorder (ASD) are currently conceptualized as distinct disorders. However, the relationship between these two disorders has been revisited in recent years due to evidence that they share phenotypic and genotypic expressions. This study aimed to identify ASD traits in patients with schizophrenia, and to define their demographic, psychopathological, cognitive and functional correlates. METHOD: Seventy-five schizophrenia patients (20 females, mean age 42 ± 12) were evaluated with the Autism Diagnostic Observation Schedule (ADOS) and the Autism Diagnostic Interview-Revised (ADI-R). Participants were also assessed with clinical, neuropsychological, and psychosocial functioning measures. RESULTS: Of the 75 patients, 47 were negative to all the autism scales administered (ADOS-TOT-NEG), 21 patients were positive to the ADOS Language sub-domain (ADOS-L-POS), 21 patients were positive to the ADOS Reciprocal Social Interaction (RSI) sub-domain (ADOS-RSI-POS), 14 patients were positive to the ADOS Total scale (ADOS-TOT-POS), and nine patients were positive to the ADI-R scale (ADI-R-POS). Demographic (duration of illness), psychopathological (negative symptoms and general psychopathology), and cognitive (working memory and processing speed) differences emerged between schizophrenic patients with and without ASD traits, while no differences in psychosocial functioning were detected. Results of this study indicate the existence, in a sample of patients with a diagnosis of schizophrenia, of a distinct group of subjects with ASD features, characterized by specific symptomatological and cognitive profile. CONCLUSIONS: These findings may contribute to better characterize patients with schizophrenia in order to develop new procedures and therapeutic tools in a more personalized perspective.


Assuntos
Transtorno do Espectro Autista/fisiopatologia , Disfunção Cognitiva/fisiopatologia , Esquizofrenia/fisiopatologia , Adulto , Transtorno do Espectro Autista/epidemiologia , Disfunção Cognitiva/epidemiologia , Comorbidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Esquizofrenia/epidemiologia
10.
Psychol Med ; 48(8): 1359-1366, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29017620

RESUMO

BACKGROUND: The increased use of the MATRICS Consensus Cognitive Battery (MCCB) to investigate cognitive dysfunctions in schizophrenia fostered interest in its sensitivity in the context of family studies. As various measures of the same cognitive domains may have different power to distinguish between unaffected relatives of patients and controls, the relative sensitivity of MCCB tests for relative-control differences has to be established. We compared MCCB scores of 852 outpatients with schizophrenia (SCZ) with those of 342 unaffected relatives (REL) and a normative Italian sample of 774 healthy subjects (HCS). We examined familial aggregation of cognitive impairment by investigating within-family prediction of MCCB scores based on probands' scores. METHODS: Multivariate analysis of variance was used to analyze group differences in adjusted MCCB scores. Weighted least-squares analysis was used to investigate whether probands' MCCB scores predicted REL neurocognitive performance. RESULTS: SCZ were significantly impaired on all MCCB domains. REL had intermediate scores between SCZ and HCS, showing a similar pattern of impairment, except for social cognition. Proband's scores significantly predicted REL MCCB scores on all domains except for visual learning. CONCLUSIONS: In a large sample of stable patients with schizophrenia, living in the community, and in their unaffected relatives, MCCB demonstrated sensitivity to cognitive deficits in both groups. Our findings of significant within-family prediction of MCCB scores might reflect disease-related genetic or environmental factors.


Assuntos
Disfunção Cognitiva/diagnóstico , Família/psicologia , Esquizofrenia/complicações , Psicologia do Esquizofrênico , Adulto , Idoso , Cognição , Consenso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pacientes Ambulatoriais/psicologia , Escalas de Graduação Psiquiátrica , Psicometria
11.
Acta Psychiatr Scand ; 138(3): 253-266, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29984409

RESUMO

OBJECTIVE: The study aimed to explore premorbid academic and social functioning in patients with schizophrenia, and its associations with the severity of negative symptoms and neurocognitive impairment. METHOD: Premorbid adjustment (PA) in patients with schizophrenia was compared to early adjustment in unaffected first-degree relatives and healthy controls. Its associations with psychopathology, cognition, and real-life functioning were investigated. The associations of PA with primary negative symptoms and their two factors were explored. RESULTS: We found an impairment of academic and social PA in patients (P ≤ 0.000001) and an impairment of academic aspects of early adjustment in relatives (P ≤ 0.01). Patients with poor PA showed greater severity of negative symptoms (limited to avolition after excluding the effect of depression/parkinsonism), working memory, social cognition, and real-life functioning (P ≤ 0.01 to ≤0.000001). Worse academic and social PA were associated with greater severity of psychopathology, cognitive impairment, and real-life functioning impairment (P ≤ 0.000001). Regression analyses showed that worse PA in the academic domain was mainly associated to the impairment of working memory, whereas worse PA in the social domain to avolition (P ≤ 0.000001). CONCLUSION: Our findings suggest that poor early adjustment may represent a marker of vulnerability to schizophrenia and highlight the need for preventive/early interventions based on psychosocial and/or cognitive programs.


Assuntos
Desempenho Acadêmico/psicologia , Transtornos Cognitivos/psicologia , Disfunção Cognitiva/psicologia , Esquizofrenia/diagnóstico , Desempenho Acadêmico/tendências , Adulto , Idoso , Cognição/fisiologia , Transtornos Cognitivos/diagnóstico , Disfunção Cognitiva/diagnóstico , Depressão/epidemiologia , Depressão/psicologia , Feminino , Humanos , Masculino , Memória de Curto Prazo/fisiologia , Pessoa de Meia-Idade , Motivação , Escalas de Graduação Psiquiátrica/normas , Psicopatologia , Esquizofrenia/epidemiologia , Esquizofrenia/terapia , Psicologia do Esquizofrênico , Índice de Gravidade de Doença , Ajustamento Social , Comportamento Social
12.
Pharmacogenomics J ; 17(2): 146-154, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-26856250

RESUMO

The search for biomarkers of response to antipsychotic medications is hindered by difficulties inherent in the topic or related to persistent methodological difficulties, such as high rates of anticipated discontinuation and consequent distortions in the imputation of missing data. Because early response to antipsychotics represents a sufficiently reliable index of the subsequent treatment response in patients with schizophrenia, we undertook a real-world, genome-wide association study (GWAS) with the aim of identifying genetic predictors of response to risperidone after 2 weeks in 86 patients with schizophrenia. Limited to the associations reaching significance in the GWAS, confirmatory analysis relative to risperidone response over 9 months was also designed involving 97 patients (European only) enroled in the CATIE (Clinical Antipsychotic Trials of Intervention Effectiveness) genetic substudy. The GWAS revealed a significant association (false discovery rate 0.02) of the single-nucleotide polymorphism rs2133450 inside the GRM7 gene with Emsley's positive domain derived from the positive and negative syndrome scale (PANSS). Patients with the rs2133450 CC genotype presented poorer improvement in the positive domain over 2 weeks, with odds ratios of 12.68 (95% CI, 3.51-45.76) and 6.95 (95% confidence interval (CI), 2.37-20.37) compared with patients with the AA and AC genotypes, respectively. Compared with A homozygotes, rs2133450 C homozygotes enroled in the CATIE-derived confirmatory analysis showed less improvement in Emsley's positive, excited and depression domains, positive and general PANSS subtypes, and total PANSS after 9 months of treatment with risperidone. The original GWAS and the CATIE-derived confirmatory analysis support the proposal that the rs2133450 may have translational relevance as a predictor of response to risperidone.


Assuntos
Antipsicóticos/uso terapêutico , Testes Farmacogenômicos/métodos , Variantes Farmacogenômicos , Polimorfismo de Nucleotídeo Único , Receptores de Glutamato Metabotrópico/genética , Risperidona/uso terapêutico , Esquizofrenia/tratamento farmacológico , Psicologia do Esquizofrênico , Adulto , Feminino , Frequência do Gene , Estudo de Associação Genômica Ampla , Genótipo , Heterozigoto , Homozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Farmacogenética , Fenótipo , Valor Preditivo dos Testes , Fatores de Risco , Esquizofrenia/diagnóstico , Esquizofrenia/genética , Fatores de Tempo , Resultado do Tratamento
13.
Nat Mater ; 15(9): 1037-46, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27213956

RESUMO

A multitude of micro- and nanoparticles have been developed to improve the delivery of systemically administered pharmaceuticals, which are subject to a number of biological barriers that limit their optimal biodistribution. Bioinspired drug-delivery carriers formulated by bottom-up or top-down strategies have emerged as an alternative approach to evade the mononuclear phagocytic system and facilitate transport across the endothelial vessel wall. Here, we describe a method that leverages the advantages of bottom-up and top-down strategies to incorporate proteins derived from the leukocyte plasma membrane into lipid nanoparticles. The resulting proteolipid vesicles-which we refer to as leukosomes-retained the versatility and physicochemical properties typical of liposomal formulations, preferentially targeted inflamed vasculature, enabled the selective and effective delivery of dexamethasone to inflamed tissues, and reduced phlogosis in a localized model of inflammation.


Assuntos
Materiais Biomiméticos/metabolismo , Portadores de Fármacos/metabolismo , Proteolipídeos/metabolismo , Inflamação/patologia , Leucócitos/citologia , Proteínas de Membrana/metabolismo
15.
Compr Psychiatry ; 73: 61-83, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27918948

RESUMO

AIM: Increasing literature has shown the usefulness of a dimensional approach to autism. The present study aimed to determine the psychometric properties of the Adult Autism Subthreshold Spectrum (AdAS Spectrum), a new questionnaire specifically tailored to assess subthreshold forms of autism spectrum disorder (ASD) in adulthood. METHODS: 102 adults endorsing at least one DSM-5 symptom criterion for ASD (ASDc), 143 adults diagnosed with a feeding and eating disorder (FED), and 160 subjects with no mental disorders (CTL), were recruited from 7 Italian University Departments of Psychiatry and administered the following: SCID-5, Autism-Spectrum Quotient (AQ), Ritvo Autism and Asperger Diagnostic Scale 14-item version (RAADS-14), and AdAS Spectrum. RESULTS: The AdAS Spectrum demonstrated excellent internal consistency for the total score (Kuder-Richardson's coefficient=.964) as well as for five out of seven domains (all coefficients>.80) and sound test-retest reliability (ICC=.976). The total and domain AdAS Spectrum scores showed a moderate to strong (>.50) positive correlation with one another and with the AQ and RAADS-14 total scores. ASDc subjects reported significantly higher AdAS Spectrum total scores than both FED (p<.001) and CTL (p<.001), and significantly higher scores on the Childhood/adolescence, Verbal communication, Empathy, Inflexibility and adherence to routine, and Restricted interests and rumination domains (all p<.001) than FED, while on all domains compared to CTL. CTL displayed significantly lower total and domain scores than FED (all p<.001). A significant effect of gender emerged for the Hyper- and hyporeactivity to sensory input domain, with women showing higher scores than men (p=.003). A Diagnosis* Gender interaction was also found for the Verbal communication (p=.019) and Empathy (p=.023) domains. When splitting the ASDc in subjects with one symptom criterion (ASD1) and those with a ASD, and the FED in subjects with no ASD symptom criteria (FED0) and those with one ASD symptom criterion (FED1), a gradient of severity in AdAS Spectrum scores from CTL subjects to ASD patients, across FED0, ASD1, FED1 was shown. CONCLUSIONS: The AdAS Spectrum showed excellent internal consistency and test-retest reliability and strong convergent validity with alternative dimensional measures of ASD. The questionnaire performed differently among the three diagnostic groups and enlightened some significant effects of gender in the expression of autistic traits.


Assuntos
Transtorno do Espectro Autista/diagnóstico , Transtorno Autístico/diagnóstico , Inquéritos e Questionários , Adolescente , Adulto , Estudos de Casos e Controles , Transtornos da Alimentação e da Ingestão de Alimentos/diagnóstico , Feminino , Humanos , Masculino , Sintomas Prodrômicos , Psicometria , Reprodutibilidade dos Testes , Adulto Jovem
16.
Neuropsychol Rehabil ; 27(3): 369-408, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26372793

RESUMO

Here we report the assessment and treatment of a 6-year-old boy (L.G.) who was referred to us for congenital prosopagnosia (CP). We investigated his performance using a test battery and eye movement recordings pre- and post-training. L.G. showed deficits in recognising relatives and learning new faces, and misrecognition of unfamiliar people. Eye movement recordings showed that L.G. focused on the lower part of stimuli in naming tasks based on familiar or unfamiliar incomplete or complete faces. The training focused on improving his ability to explore internal features of faces, to discriminate specific facial features of familiar and unfamiliar faces, and to provide his family with strategies to use in the future. At the end of the training programme L.G. no longer failed to recognise close and distant relatives and classmates and did not falsely recognise unknown people.


Assuntos
Medições dos Movimentos Oculares , Testes Neuropsicológicos , Prosopagnosia/congênito , Criança , Movimentos Oculares , Humanos , Masculino , Reconhecimento Visual de Modelos , Prosopagnosia/fisiopatologia , Prosopagnosia/psicologia , Prosopagnosia/reabilitação
17.
Neurocase ; 21(6): 697-706, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25360817

RESUMO

We report the case of FP affected by personal and extrapersonal neglect and a body representation deficit characterized by delusional ideas. When FP performed the human figure, he placed body parts to the left, despite his extrapersonal neglect. Differently, when he performed the car figure, he placed all parts to the right, in line with his deficit. Comparing FP with a small patient group with the same clinical features without delusional ideas about body emerged that he was the only one to suffer from a specific body representation deficit characterized by a lack of body ownership sense.


Assuntos
Imagem Corporal , Delusões/patologia , Transtornos da Percepção/patologia , Acidente Vascular Cerebral/complicações , Córtex Cerebral/patologia , Delusões/etiologia , Lobo Frontal/patologia , Lateralidade Funcional , Hemiplegia/etiologia , Hemiplegia/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Transtornos da Percepção/etiologia , Acidente Vascular Cerebral/patologia , Acidente Vascular Cerebral/psicologia
18.
Angew Chem Int Ed Engl ; 54(52): 15880-3, 2015 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-26566072

RESUMO

Non-oxidative dehydrogenation of propane to propene is an established large-scale process that, however, faces challenges, particularly in catalyst development; these are the toxicity of chromium compounds, high cost of platinum, and catalyst durability. Herein, we describe the design of unconventional catalysts based on bulk materials with a certain defect structure, for example, ZrO2 promoted with other metal oxides. Comprehensive characterization supports the hypothesis that coordinatively unsaturated Zr cations are the active sites for propane dehydrogenation. Their concentration can be adjusted by varying the kind of ZrO2 promoter and/or supporting tiny amounts of hydrogenation-active metal. Accordingly designed Cu(0.05 wt %)/ZrO2 -La2 O3 showed industrially relevant activity and durability over ca. 240 h on stream in a series of 60 dehydrogenation and oxidative regeneration cycles between 550 and 625 °C.

19.
J Phys Condens Matter ; 35(40)2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37364587

RESUMO

Polarization dependent x-ray absorption spectroscopy was used to study the magnetic ground state and the orbital occupation in bulk-phase VI3van der Waals crystals below and above the ferromagnetic and structural transitions. X-ray natural linear dichroism and x-ray magnetic circular dichroism spectra acquired at the VL2,3edges are compared against multiplet cluster calculations within the frame of the ligand field theory to quantify the intra-atomic electronic interactions at play and evaluate the effects of symmetry reduction occurring in a trigonally distorted VI6unit. We observed a non zero linear dichroism proving the presence of an anisotropic charge density distribution around the V3+ion due to the unbalanced hybridization between the vanadium and the ligand states. Such hybridization acts as an effective trigonal crystal field, slightly lifting the degeneracy of thet2g2ground state. However, the energy splitting associated to the distortion underestimates the experimental band gap, suggesting that the insulating ground state is stabilized by Mott correlation effects rather than via a Jahn-Teller mechanism. Our results clarify the role of the distortion in VI3and establish a benchmark for the study of the spectroscopic properties of other van der Waals halides, including emerging 2D materials with mono and few-layers thickness, whose fundamental properties might be altered by reduced dimensions and interface proximity.

20.
Adv Mater ; 35(24): e2211260, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36863934

RESUMO

Nitrous oxide, N2 O, exhibits unique reactivity in oxidation catalysis, but the high manufacturing costs limit its prospective uses. Direct oxidation of ammonia, NH3 , to N2 O can ameliorate this issue but its implementation is thwarted by suboptimal catalyst selectivity and stability, and the lack of established structure-performance relationships. Systematic and controlled material nanostructuring offers an innovative approach for advancement in catalyst design. Herein low-valent manganese atoms stabilized on ceria, CeO2 , are discovered as the first stable catalyst for NH3 oxidation to N2 O, exhibiting two-fold higher productivity than the state-of-the-art. Detailed mechanistic, computational and kinetic studies reveal CeO2 as the mediator of oxygen supply, while undercoordinated manganese species activate O2 and facilitate N2 O evolution via NN bond formation between nitroxyl, HNO, intermediates. Synthesis via simple impregnation of a small metal quantity (1 wt%) predominantly generates isolated manganese sites, while full atomic dispersion is achieved upon redispersion of sporadic oxide nanoparticles during reaction, as confirmed by advanced microscopic analysis and electron paramagnetic resonance spectroscopy. Subsequently, manganese speciation is maintained, and no deactivation is observed over 70 h on stream. CeO2 -supported isolated transition metals emerge as a novel class of materials for N2 O production, encouraging future studies to evaluate their potential in selective catalytic oxidations at large.

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