Mechanism Of Oxidation Research Articles

Mechanistic Insights into the Aerobic Oxidation of 2,5-Bis(hydroxymethyl)furfural to 2,5-Furandicarboxylic Acid on Pd Catalysts.

2,5-Furandicarboxylic acid (FDCA) is one of the top selected value-added chemicals, which can be obtained by the aerobic oxidation of 2,5-bis(hydroxymethyl)furfural (BHMF) over a Pd-based catalyst. However, the elucidation of the reaction mechanism was hindered by its rapid kinetics. Herein, employing the density functional theory (DFT) calculations, we delve into the detailed reaction pathways of the BHMF oxidation into FDCA over Pd(111) and PdHx(111) identifying the rate-determining steps. The results demonstrated that 2,5-diformylfuran (DFF) and 5-formyl-2-furancarboxylic acid (FFCA) are the important intermediates, while the oxidation of FFCA is the rate-limiting step with the energy barrier of 0.68 and 0.51 eV on Pd(111) and PdH1/4(111), respectively. By comparison of the d-band center of Pd(111) and PdHx(111) surfaces and the overall energy barrier of this reaction over these two surfaces, it makes clear that the occupation of H atoms in the Pd bulk changes the surface electronic structures and enhances the binding energy of BHMF with the PdHx surface, which consequently speeds up the conversion of BHMF into FDCA. Water plays a crucial role in facilitating the activation of O2 via the H-transfer by constructing a hydrogen-bonding chain with the O2 and OH*. The activation of molecular oxygen experiences enhancement through the synergy of OH* and H2O, resulting in the production of actomic oxygen (O*). Both O* and OH* actively participate in the BHMF oxidation, where O* improved the activation toward initial critical reaction pathways on Pd(111) while OH* exhibited its pronounced impact on the latter two key processes on both Pd(111) and PdH1/4(111). This study will contribute to well understanding the oxidation mechanism of BHMF into FDCA over Pd-based catalysts and establish a theoretical framework for the potential development of an effective catalyst.

The Dissolution Behavior of Pyrite and Chalcopyrite in Their Mixture During Low-Temperature Pressure Oxidation: A Kinetic Analysis

The research presented in this paper focused on the pressure leaching of pyrite and chalcopyrite in their mixture at a low temperature (100 ± 2 °C). The mathematical models of chalcopyrite and pyrite dissolution in their mixture are obtained. According to kinetic analyses, the oxidation process of chalcopyrite and pyrite is limited by intra-diffusion limitations. An elemental sulfur film passivates the surface of chalcopyrite and pyrite particles according to the SEM and EDX mappings. The data show that the oxidation mechanism of chalcopyrite and pyrite in their mixture has changed. The activation energy values of chalcopyrite and pyrite have increased from 51.2 to 59.0 kJ/mol, respectively. The oxidation degree of pyrite in its mixture with chalcopyrite increased significantly from 54.5 to 80.3% within 0–230 min. Copper and iron ions during oxidation were not associated with an increase in the dissolution degree of pyrite with the addition of chalcopyrite. The positive effect of pyrite in its mixture with chalcopyrite on its oxidation degree can be explained by the formation of an electrochemical bond between the minerals. Microphotographs and EDX mapping confirm that the positive effect of the chalcopyrite additive is correlated with a decrease in the formation of elemental sulfur on the pyrite surface. With no formation of conglomerates, the mineral’s sulfur content becomes more uniform, confirming the sulfides’ interaction with each other.

A comprehensive review of arsenic-induced neurotoxicity: Exploring the role of glial cell pathways and mechanisms.

The review aims to examine the neurotoxic effects of arsenic, particularly exploring the roles of glial cells-astrocytes, microglia, and oligodendrocytes, amid its widespread environmental contamination and impact on cognitive impairments. It highlights the role of altered neurotrophin and growth factor signaling in disrupting neuronal health and cognitive performance. It elucidates the intricate interactions between oxidative stress, DNA damage, neurotransmitter disruption, and cellular signaling alterations, underscoring the vital importance of the glial cells. These cells are crucial for preserving neural health and responding to environmental toxins, and arsenic disrupts their functions, resulting in decreased antioxidative responses, induction of inflammatory pathways, and subsequent neuronal dysfunction. The brain's cytotoxic impact arises from a complex network of cellular responses, with pathways such as MAPK, transcription factor and autophagy signaling to play critical roles in mediating these dysregulated inflammation and oxidative stress mechanisms. The detailed exploration into specific impacts of arsenic on glial cell morphology, activation, and mitochondrial functions illuminates the cascade of neuroinflammatory and neurodegenerative changes that may be triggered upon arsenic exposure. The review recommends a multidisciplinary research approach by emphasizing the significance of the brain's microenvironment, methylation processes, and the enzyme AS3MT in arsenic neurotoxicity. It calls for converging environmental science, neurobiology, and toxicology to develop targeted interventions for preventing and mitigating arsenic's neurotoxic effects. This in-depth exploration into glial cell dynamics aims to advance public health and neurotoxicology research, striving to devise strategies that reduce the cognitive and neurodegenerative damage caused by arsenic, thereby enhancing global health outcomes.

Theoretical Insights into Methanol Electro-Oxidation on NiPd Nanoelectrocatalysts: Investigating the Carbonate–Palladium Oxide Pathway and the Role of Water and OH Adsorption

We conducted a theoretical and experimental study on the electro-oxidation of methanol (MOR) on NixPdy nanoparticles. The results are presented in terms of kinetic parameters, surface concentrations, and peak currents, showing significant differences between three main compositions: Ni3Pd1, Ni1Pd1, and Ni1Pd3. The kinetic mechanism adopted for accounting the linear voltammetry experiments performed follows the carbonate–palladium oxide pathway of the MOR. Numerical simulations of the kinetic equations, fitted to experimental data obtained at varying methanol concentrations, allowed us to distinguish the adsorption contributions of methanol, water, and OH ions from the nonlinear contribution associated with palladium oxide and carbon dioxide production. The synergistic effects of Ni:Pd nanoalloys on the MOR were then assessed by analyzing the behavior and tendencies of the reaction rate constants for different bulk methanol concentrations. Our results suggest that a higher Pd content favors more efficient oxidation mechanisms by reducing the formation of intermediate products that cause surface poisoning, such as CO, carbonates, or palladium oxide. However, as the proportion of Ni increases, an increase in the concentration of adsorbed OH is observed, which dominates the blocking of active sites even greater than the palladium oxide blocking.

New insights into the Fe(III)-activated peroxyacetic acid: oxidation properties and mechanism.

Iron-activated peroxyacetic acid (PAA) represents an innovative advanced oxidation process (AOP). However, the efficiency of PAA activation by Fe(III) is often underestimated due to the widespread assumption that Fe(III) exhibits much lower ability than Fe(II) to activate PAA. Herein, the oxidative degradation of Rhodamine B (RhB) by Fe(III)-activated PAA process was investigated, and some new insights into the performance and mechanism of the Fe(III)/PAA system were presented. Although the reaction rate of Fe(III) with PAA was slightly slower than that of Fe(II), Fe(III) was still able to activate PAA effectively, and the degradation efficiency of RhB was comparable to that of the Fe(II)/PAA system after 30 min of reaction. Notably, the Fe(III)/PAA system demonstrated superior oxidation capacity compared to conventional oxidant systems, including Fe(III)/H2O2, Fe(III)/PDS, Fe(III)/PMS. The degradation efficiency varied significantly across different water substrates. While Cl- exhibited a certain inhibitory effect on the degradation of RhB, H2PO4- exerted a pronounced inhibitory influence, whereas NO3-, SO42- and HCO3- had negligible effects. The increase of humic acid (HA) showed a facilitating effect in the initial stage, followed by an inhibitory effect. Furthermore, mechanistic studies indicated that H2O2 in PAA solution was not effectively activated. The degradation of RhB primarily occurred through a non-radical pathway generated by PAA activation, with the contribution of reactive species (RS) in the order of FeIVO2+ >•OH > R-O• (CH3COO• and CH3COOO•). RhB degradation was achieved not only by attacking the chromophore of RhB molecules, but also the effective destruction of the stable structures such as benzene rings. This study enhances the understanding of Fe(III)-activated PAA and broadens its potential for developing and applying PAA-based AOPs.

Study on the performance and mechanism of graphene oxide / polyurethane composite modified asphalt

In order to enhance the aging resistance, high temperature stability and low temperature crack resistance of asphalt pavement materials, 0.06% oxidized graphene (GO) and 12% polyurethane (PU) were used as composite modifiers to modify the base asphalt. The RTFOT test was conducted to evaluate the anti-aging performance of the modified asphalt. The rheological properties of GO/PU composite modified asphalt were evaluated. SEM and FTIR tests were used to analyze the microstructure of GO/PU modified asphalt. The results show that the basic performance of composite modified asphalt meets the requirements and the anti-aging performance is improved. The improvement of rutting factor and frequency scanning master curve shows its better anti-rutting deformation ability. The strain recovery R-value for the composite modified bitumen increased by 20.7% at a stress level of 0.1 kPa, and the unrecoverable creep compliance Jnr decreased by 76.0%, showing excellent viscoelastic properties. The creep stiffness S of composite modified asphalt decreased by 31.2% at−12 °C, indicating that it had good low temperature rheological properties. The surface of the modified composite asphalt is relatively smooth, exhibiting a stable network structure, thus solving the PU segregation problem in the matrix asphalt.The change of infrared spectrum absorption peak shows that reaction between isocyanate groups in polyurethane and aromatic esters in bitumen, GO oxidizes with the-CH functional group in asphalt, and the content of C = C double bond changes during the modification process, indicating that the modification of asphalt by GO and PU is a composite modification based on chemical modification and supplemented by physical modification.

Design and synthesis of Pt/TiO2 catalyst with abundant surface hydroxyl for formaldehyde oxidation.

Catalytic oxidation of formaldehyde (HCHO) is a highly effective method for indoor HCHO removal. However, many aspects of the catalytic mechanism remain unclear, making the optimization of catalysts largely empirical. Herein, we report a coupled experimental and computational study of Pt/TiO2 catalysts, with special focus on the functional roles of surface oxygen vacancies and hydroxyl groups in the catalytic oxidation of HCHO. DFT calculations combined with control experiments revealed that the formation of surface oxygen vacancies on TiO2 and their capability in facilitating H2O dissociation are strongly dependent on the exposed facets. Correlating these facet-dependent properties with the determined activity further indicated that the catalytic performance is directly related to the abundance of surface hydroxyl groups, rather than surface oxygen vacancies as commonly assumed. Guided by these insights, we employed a combination of facet-engineering and alkali metal modification strategies to design a potassium-modified Pt/TiO2 catalyst with predominantly exposed {100} facets (denoted as Pt/TiO2{100}-K). The Pt/TiO2{100}-K catalyst showed an impressively high mass-specific reaction rate of 105.7 μmol gPt-1 s-1, along with fairly good stability and moisture tolerance. Further investigations using in situ DRIFTS coupled with on-line GC provided additional insight into the reaction mechanism of HCHO oxidation over the Pt/TiO2{100}-K catalyst.

Electrochemical Oxidation Mechanism of Tetracycline in Various Supporting Electrolytes Based on a Boron‐Doped Diamond Anode

Electrochemical Oxidation Mechanism of Tetracycline in Various Supporting Electrolytes Based on a Boron‐Doped Diamond Anode

Examining memory reconsolidation as a mechanism of nitrous oxide's antidepressant action.

There is an ongoing need to identify novel pharmacological agents for the effective treatment of depression. One emerging candidate, which has demonstrated rapid-acting antidepressant effects in treatment-resistant groups, is nitrous oxide (N2O)-a gas commonly used for sedation and pain management in clinical settings and with a range of pharmacological effects, including antagonism of NMDA glutamate receptors. A growing body of evidence suggests that subanaesthetic doses of N2O (50%) can interfere with the reconsolidation of maladaptive memories in healthy participants and across a range of disorders. Negative biases in memory play a key role in the onset, maintenance, and recurrence of depressive episodes, and the disruption of affective memory reconsolidation is one plausible mechanism through which N2O exerts its therapeutic effects. Understanding N2O's mechanisms of action may facilitate future treatment development in depression. In this narrative review, we introduce the evidence supporting an antidepressant profile of N2O and evaluate its clinical use compared to other treatments. With a focus on the specific memory processes that are thought to be disrupted in depression, we consider the effects of N2O on memory reconsolidation and propose a memory-based mechanism of N2O antidepressant action.

Enhancing Catalytic Removal of Autoexhaust Soot Particles via the Modulation of Interfacial Oxygen Vacancies in Cu/CeO2 Catalysts.

The purification efficiency of autoexhaust carbon strongly depends on the heterogeneous interface structure between active metal and oxide, which can modulate the local electronic structure of defect sites to promote the activation of reactant molecules. Herein, the high-dispersion CuO clusters supported on the well-defined CeO2 nanorods were prepared using the complex deposition slow method. The formation of heteroatomic Cu+-Ov-Ce3+ interfacial structural units as active sites can capture electrons to achieve activation of the NO and O2 molecules. Among all of the synthesized catalysts, the Cu10/CeO2 catalyst exhibits superior catalytic performance (T50 = 351 °C) along with remarkable tolerance to H2O and SO2 in the removal of soot particles. Through a combination of comprehensive characterizations and density functional theory calculations, it is proposed that the interfacial Cu+-Ov-Ce3+ site, acting as an electron enrichment center, can capture electrons from the Cu d-band and Ce d/f-band to obtain high delocalized electron density, and then enhance the oxidation of NO to NO2, which plays a crucial role in the NOx-assisted catalytic mechanism for soot oxidation. This study presents a novel strategy for developing highly efficient catalysts that exhibit resistance to H2O and SO2, aimed at enhancing the removal of soot particles.

Hydrogen Sensing via Heterolytic H2 Activation at Room Temperature by Atomic Layer Deposited Ceria.

Ultrathin atomic layer deposited ceria films (< 20 nm) are capable of H2 heterolytic activation at room temperature, undergoing a significant reduction regardless of the absolute pressure, as measured under in-situ conditions by near ambient pressure X-ray photoelectron spectroscopy. ALD-ceria can gradually reduce as a function of H2 concentration under H2/O2 environments, especially for diluted mixtures below 10%. At room temperature, this reduction is limited to the surface region, where the hydroxylation of the ceria surface induces a charge transfer towards the ceria matrix, reducing Ce4+ cations to Ce3+. Thus, ALD-ceria replicates the expected sensing mechanism of metal oxides at low temperatures without using any noble metal decorating the oxide surface to enhance H2 dissociation. The intrinsic defects of the ALD deposit seem to play a crucial role since the post-annealing process capable of healing these defects leads to decreased film reactivity. The sensing behavior was successfully demonstrated in sensor test structures by resistance changes towards low concentrations of H2 at low operating temperatures without using noble metals. These promising results call for combining ALD-ceria with more conductive metal oxides, taking advantage of the charge transfer at the interface and thus modifying the depletion layer formed at the heterojunction.

The Future of MXenes: Exploring Oxidative Degradation Pathways and Coping with Surface/Edge Passivation Approach.

The MXene, which is usually transition metal carbide, nitride, and carbonitride, is one of the emerging family of 2D materials, exhibiting considerable potential across various research areas. Despite theoretical versatility, practical application of MXene is prohibited due to its spontaneous oxidative degradation. This review meticulously discusses the factors influencing the oxidation of MXenes, considering both thermodynamic and kinetic point of view. The potential mechanisms of oxidation are systematically introduced, based on experimental and theoretical models. Typically, the surfaces and edges of MXenes are susceptible to oxidation, as the surface terminal groups are easily attacked by oxygen and water molecules, ultimately leading to structural deformation. To retard oxidative degradation, ligand mediated surface/edge passivation is suggested as a promising strategy. In this regard, detailed passivation strategies for MXenes are systematically explained based on the types of chemistry at the MXene-ligand interface-covalent bonding, electrostatic interactions, and hydrogen bonding-and the type of stabilizing moieties-organic, inorganic, biomolecules, and polymers. The retardation of oxidation is discussed in relation with the interaction type and passivating moiety. This review aims to catalyze future research to identify efficient and cost-effective ligands for the surface engineering of MXenes, enhancing their oxidation stability.

Disruption of midgut homeostasis by microplastics in Spodoptera frugiperda: Insights into inflammatory and oxidative mechanisms.

Microplastics have evolved as widespread contaminants in terrestrial and aquatic environments, raising significant environmental concerns due to their persistence and bioaccumulation. In this study, we investigated the toxicity of polyethylene microplastics (PE-MPs) on the agricultural insect, Spodoptera frugiperda. Maize leaves containing three sizes (0.5 μm, 5 μm, and 50 μm) of PE-MPs were fed to fall armyworm larvae for 12 days at concentrations of 1.25 g/ L, 5 g/L, and 20 g/L. The results showed that smaller size and higher concentration of microplastics led to increased toxicity. Furthermore, different sizes and maximum concentrations of PE-MPs were selected for subsequent experiments to observe changes in histological and enzymatic biomarkers, midgut microbiome, and metabolic responses. Following PE-MPs exposure, inflammation signs and oxidative stress were detected in the midgut. Significant changes were also observed in midgut microbiota and metabolomes, most related with oxidative stress, inflammatory disorders, and energy metabolism. These results provide evidence of midgut damage and alterations in the microbiota and metabolome of S. frugiperda because of PE-MPs exposure, highlighting the harm that microplastics can inflict on agricultural insects. Additionally, the study lays a theoretical foundation for future research on the transmission of microplastics through the food chain in agricultural ecosystems.

Isotopic Transient Kinetic Analysis of Soot Oxidation on Mn3O4, Mn3O4-CeO2, and CeO2 Catalysts in Tight Contact Conditions.

The reaction mechanism of soot oxidation on Mn (Mn3O4), Mn-Ce (Mn3O4-CeO2), and Ce (CeO2) catalysts in tight contact conditions was investigated using ITKA (isotopic transient kinetic analysis). The obtained results suggest that lattice-bulk oxygen from all studied catalysts takes part in the soot oxidation process but with varying relative contributions: for the Ce catalyst, this contribution is practically 100%, whereas with decreasing Ce content in Mn-Ce catalysts, the significance of lattice-bulk oxygen for soot oxidation diminishes. For the Mn catalyst, it is estimated to be below 50%. Moreover, strong interactions between Mn and Ce ions were observed, increasing oxygen mobility in the catalyst crystal lattice and affecting the activity of Mn-Ce catalysts.

Computational exploration of the electrochemical oxidation mechanism of thiocyanate catalyzed by cobalt-phthalocyanines.

In this study, we focused on the mechanism of the electrocatalytic oxidation of thiocyanate, which in traditional electrodes typically requires high overpotentials. As models for reducing these overpotentials and catalyzing the reaction, we used a set of modified cobalt phthalocyanines (CoPc), known as electrocatalysts. Using DFT calculations, we explored how modifications to CoPc by adding electron-donating and withdrawing groups and the coordination of 4-amino thiophenol impact the oxidation process. The reaction mechanism for the electrooxidation of thiocyanate has remained elusive, where only the reaction products have been properly identified, including hydrogen cyanide and sulfate ions at pH 4. The approach for understanding the reaction was considering the formation of an (SCN)2 dimer as an intermediate that is a suitable precursor of the products of the reaction. Our findings showed that electron-donating groups and 4-amino thiophenol coordination lowered oxidation potentials, enhancing electrocatalytic efficiency and promoting thiocyanate radical formation and release before dimerization occurs. In contrast, electron-withdrawing groups facilitated dimerization while attached to cobalt, albeit with lower electrocatalytic proficiency. This study highlights the crucial role of CoPc modifications in thiocyanate oxidation, demonstrating the potential for improved electrocatalytic processes through tailored catalyst design.

Deciphering the safeguarding role of cysteine residues in p53 against H2O2-induced oxidation using high-resolution native mass spectrometry

The transcription factor p53 is exquisitely sensitive and selective to a broad variety of cellular environments. Several studies have reported that oxidative stress weakens the p53-DNA binding affinity for certain promoters depending on the oxidation mechanism. Despite this body of work, the precise mechanisms by which the physiologically relevant DNA-p53 tetramer complex senses cellular stresses caused by H2O2 are still unknown. Here, we employed native mass spectrometry (MS) and ion mobility (IM)-MS coupled to chemical labelling and H2O2-induced oxidation to examine the mechanism of redox regulation of the p53-p21 complex. Our approach has found that two reactive cysteines in p53 protect against H2O2-induced oxidation by forming reversible sulfenates.

Advances in Oxygen Evolution Reaction Electrocatalysts via Direct Oxygen-Oxygen Radical Coupling Pathway.

Oxygen evolution reaction (OER) is a cornerstone of various electrochemical energy conversion and storage systems, including water splitting, CO2/N2 reduction, reversible fuel cells, and rechargeable metal-air batteries. OER typically proceeds through three primary mechanisms: adsorbate evolution mechanism (AEM), lattice oxygen oxidation mechanism (LOM), and oxide path mechanism (OPM). Unlike AEM and LOM, the OPM proceeds via direct oxygen-oxygen radical coupling that can bypass linear scaling relationships of reaction intermediates in AEM and avoid catalyst structural collapse in LOM, thereby enabling enhanced catalytic activity and stability. Despite its unique advantage, electrocatalysts that can drive OER via OPM remain nascent and are increasingly recognized as critical. This review discusses recent advances in OPM-based OER electrocatalysts. It starts by analyzing three reaction mechanisms that guide the design of electrocatalysts. Then, several types of novel materials, including atomic ensembles, metal oxides, perovskite oxides, and molecular complexes, are highlighted. Afterward, operando characterization techniques used to monitor the dynamic evolution of active sites and reaction intermediates are examined. The review concludes by discussing several research directions to advance OPM-based OER electrocatalysts toward practical applications.

Acidic oxygen evolution reaction via lattice oxygen oxidation mechanism: progress and challenges

The lattice oxygen mechanism (LOM) plays a critical role in the acidic oxygen evolution reaction (OER) as it provides a more efficient catalytic pathway compared to the conventional adsorption evolution mechanism (AEM). LOM effectively lowers the energy threshold of the reaction and accelerates the reaction rate by exciting the oxygen atoms in the catalyst lattice to directly participate in the OER process. In recent years, with the increase of in-depth understanding of LOM, researchers have developed a variety of iridium (Ir) and ruthenium (Ru)-based catalysts, as well as non-precious metal oxide catalysts, and optimized their performance in acidic OER through different strategies. However, LOM still faces many challenges in practical applications, including the long-term stability of the catalysts, the precise modulation of the active sites, and the application efficiency in real electrolysis systems. Here, we review the application of LOM in acidic OER, analyze its difference with the traditional AEM mechanism and the new oxide pathway mechanism (OPM) mechanism, discuss the experimental and theoretical validation methods of the LOM pathway, and prospect the future development of LOM in electrocatalyst design and energy conversion, aiming to provide fresh perspectives and strategies for solving the current challenges.

Low-temperature catalytic oxidation of ethanol over doped nickel phosphates.

This work is focused on the synthesis and performance of Ni3(PO4)2-based catalysts doped with Cu, Co, Mn, Ce, Zr, and Mg for the complete oxidation of ethanol, aiming at reducing emissions from ethanol-blended gasoline. Nickel phosphate was prepared via the co-precipitation method, followed by impregnation with the specified dopants. The catalysts were thoroughly characterized by XRD, N2-physisorption, XRF, FTIR and Raman spectroscopy, FESEM, NH3-TPD, CO2-TPD, and H2-TPR to explain their performance. All catalysts achieved complete ethanol conversion (100%) at a temperature below 320°C. The performance of the catalysts was strongly influenced by the dopant type of which Co, Ce, Mn, and Mg showed high CO2 selectivity (selectivity > 90% at 95% ethanol conversion temperature (T95)). The mechanism of oxidation is affected by the acido-basicity of the catalysts and the redox properties leading to a reaction through ethylene formation over the acid catalysts and acetaldehyde over the basic catalysts. The redox properties of the doped catalysts play a crucial role in enhancing the catalytic activity and selectivity toward CO₂, as the redox-active dopants facilitate the activation of oxygen species, which are essential for the complete oxidation of ethanol. In particular, Co and Ce demonstrated superior redox characteristics, facilitating the conversion of intermediate species and leading to higher CO2 selectivity while minimizing undesirable by-products.

Cu-Ni Oxidation Mechanism Unveiled: A Machine Learning-Accelerated First-Principles and in Situ TEM Study.

The development of accurate methods for determining how alloy surfaces spontaneously restructure under reactive and corrosive environments is a key, long-standing, grand challenge in materials science. Using machine learning-accelerated density functional theory and rare-event methods, in conjunction with in situ environmental transmission electron microscopy (ETEM), we examine the interplay between surface reconstructions and preferential segregation tendencies of CuNi(100) surfaces under oxidation conditions. Our modeling approach predicts that oxygen-induced Ni segregation in CuNi alloys favors Cu(100)-O c(2 × 2) reconstruction and destabilizes the Cu(100)-O (2√2 × √2)R45° missing row reconstruction (MRR). In situ ETEM experiments validate these predictions and show Ni segregation followed by NiO nucleation and growth in regions without MRR, with secondary nucleation and growth of Cu2O in MRR regions. Our approach based on combining disparate computational components and in situ ETEM provides a holistic description of the oxidation mechanism in CuNi, which applies to other alloy systems.