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Nickel phosphides are of particular interest because they are highly active and stable catalysts for petroleum/biorefinery and hydrogen production. Despite their significant catalytic potential, synthesizing various phase-pure nickel phosphide nanoparticles of uniform size remains a challenge. In this work, we develop a robust trioctylphosphine (TOP)-mediated route to make highly uniform phase-pure Ni12P5, Ni2P, and Ni5P4 nanoparticles. The synthetic route forms amorphous Ni70P30 nanoparticle intermediates. The reactions can be stopped at the amorphous stage when amorphous particles are desired. The amount of P incorporation can be controlled by varying the ratio of TOP to Ni(II). The mechanism for composition control involves the competition of the kinetics of two processes: the addition of the reduced Ni and the incorporation of P into Ni. Uniform Ni70P30 amorphous nanoparticles can be generated at a high TOP-to-Ni(II) ratio, where the P incorporation kinetics is made to dominate. Ni70P30 can later be transformed into phase-pure Ni12P5, Ni2P, and Ni5P4 nanocrystals of uniform size. The transformation can be controlled precisely by modulating the temperature. A UV-vis study coupled with theoretical modeling reveals Ni(0)-TOPx complexes along the synthetic path. This approach may be expanded to create other metal compounds, potentially enabling the synthesis of uniform nanoparticles of a greater variety.

Multicomponent catalysts can be designed to synergistically combine reaction intermediates at interfacial active sites, but restructuring makes systematic control and understanding of such dynamics challenging. We here unveil how reducibility and mobility of indium oxide species in Ru-based catalysts crucially control the direct, selective conversion of CO2 to ethanol. When uncontrolled, reduced indium oxide species occupy the Ru surface, leading to deactivation. With the addition of steam as a mild oxidant and using porous polymer layers to control In mobility, Ru-In2O3 interface sites are stabilized, and ethanol can be produced with superior overall selectivity (70 %, rest CO). Our work highlights how engineering of bifunctional active ensembles enables cooperativity and synergy at tailored interfaces, which unlocks unprecedented performance in heterogeneous catalysts.

Supported noble metal catalysts, ubiquitous in chemical technology, often undergo dynamic transformations between reduced and oxidized states-which influence the metal nuclearities, oxidation states, and catalytic properties. In this investigation, we report the results of in situ X-ray absorption spectroscopy, scanning transmission electron microscopy, and other physical characterization techniques, bolstered by density functional theory, to elucidate the structural transformations of a set of MgO-supported palladium catalysts under oxidative treatment conditions. As the calcination temperature increased, the as-synthesized supported metallic palladium nanoparticles underwent oxidation to form palladium oxides (at approximately 400 °C), which, at approximately 500 °C, were oxidatively fragmented to form mixtures of atomically dispersed palladium cations. The data indicate two distinct types of atomically dispersed species: palladium cations located at MgO steps and those embedded in the first subsurface layer of MgO. The former exhibit significantly higher (>500 times) catalytic activity for ethylene hydrogenation than the latter. The results pave the way for designing highly active and stable supported palladium hydrogenation catalysts with optimized metal utilization.

The reduction of CO2 is known to promote increased alkene yields from alkane dehydrogenations when the reactions are cocatalyzed. The mechanism of this promotion is not understood in the context of catalyst active-site environments because CO2 is amphoteric, and even general aspects of the chemistry, including the significance of competing side reactions, differ significantly across catalysts. Atomically dispersed chromium cations stabilized in highly siliceous MFI zeolite are shown here to enable the study of the role of parallel CO2 reduction during ethylene-selective ethane dehydrogenation. Based on infrared spectroscopy and X-ray absorption spectroscopy data interpreted through calculations using density functional theory (DFT), the synthesized catalyst contains atomically dispersed Cr cations stabilized by silanol nests in micropores. Reactor studies show that cofeeding CO2 increases stable ethylene-selective ethane dehydrogenation rates over a wide range of partial pressures. Operando X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine-structure (EXAFS) spectra indicate that during reaction at 650 °C the Cr cations maintain a nominal 2+ charge and a total Cr-O coordination number of approximately 2. However, CO2 reduction induces a change, correlated with the CO2 partial pressure, in the population of two distinct Cr-O scattering paths. This indicates that the promotional effect of parallel CO2 reduction can be attributed to a subtle change in Cr-O bond lengths in the local coordination environment of the active site. These insights are made possible by simultaneously fitting multiple EXAFS spectra recorded in different reaction conditions; this novel procedure is expected to be generally applicable for interpreting operando catalysis EXAFS data.

Soft-oxidant-assisted methane coupling has emerged as a promising pathway to upgrade methane from natural gas sources to high-value commodity chemicals, such as ethylene, at selectivities higher than those associated with oxidative (O2) methane coupling (OCM). To date, few studies have reported investigations into the electronic structure and the microscopic physical structure of catalytic active sites present in the binary metal oxide catalyst systems that are known to be effective for this reaction. Correlating the catalyst activity to specific active site structures and electronic properties is an essential aspect of catalyst design. Here, we used X-ray absorption spectroscopy at the Ca K-edge to ascertain the most probable local environment of Ca in the ZnO-supported Ca oxide catalysts. These catalysts are shown here to be active for N2O-assisted methane coupling (N2O-OCM) and have previously been reported to be active for CO2-assisted methane coupling (CO2-OCM). X-ray absorption near edge structure features at multiple Ca loadings are interpreted through simulated spectra derived from ab initio full multiple scattering calculations. These simulations included consideration of CaO structures organized in multiple spatial arrangements-linear, planar, and cubic-with separate analyses of Ca atoms in the surfaces and bulk of the three-dimensional structures. The morphology of the oxide clusters was found to influence the various regions of the X-ray absorption spectrum differently. Experiment and theory show that for low-Ca-loading catalysts (≤1 mol %), which contain sites particularly active for methane coupling, Ca primarily exists in an oxidized state that is consistent with the coordination environment of Ca ions in one- and two-dimensional clusters. In addition to their unique nanoscale structures, the spectra also indicate that these clusters have varying degrees of undercoordinated surface Ca atoms that could further influence their catalytic activities. The local Ca structure was correlated to methane coupling activity from N2O-OCM and previously reported CO2-OCM reactor studies. This study provides a unique perspective on the relationship between the catalyst physical and electronic structure and active sites for soft-oxidant-assisted methane coupling, which can be used to inform future catalyst development.

Audience: The targeted audience for this simulation is Emergency Medicine (EM) residents. Medicalstudents, advanced practice providers, and staff physicians could all also find educational merit in thisscenario.Background: Cardiovascular disease is the leading cause of death in the United States according to the CDC.1Coronary artery disease caused 375,000 deaths 2021 alone, and about 5% of all adult patients have a priorhistory of coronary artery disease.2 Furthermore, chest pain itself is a common chief complaint encounteredin the ED, with nearly 8 million visits annually occurring throughout the United States, with 10-20% of thosepatients ultimately being diagnosed with an acute coronary syndrome3, including ST-elevation myocardialinfarction (STEMI). Given this, it is essential that EM residents are well prepared to care for all patientspresenting with chest pain, regardless of the acute care or emergency setting.Throughout their training, most EM residents typically learn and evaluate patients at a large tertiary orquaternary medical center with 24-hour catheterization laboratory availability. For patients presenting withelectrocardiogram (EKG) findings consistent with STEMI, the standard of care is for the patient to undergocardiac catheterization and stent placement within 90 minutes of arrival. Unfortunately, only half of patientsliving in rural areas have a cardiac catheterization-capable facility available to them within a 60-minutedriving radius, making it difficult for those patients to undergo cardiac catheterization within the desired timeframe.4 These patients remain candidates for thrombolytic therapy, but given infrequent opportunities tolearn about and deploy thrombolytic agents during residency training, graduating EM residents may beunfamiliar with indications, dosing, and contraindications before they begin practice. Furthermore, the recent EM workforce data suggests that although there may be an oversupply of 8,000 emergency physiciansby 2030, robust practice opportunities for emergency physicians remain in rural settings.5 Althoughhistorically EM graduates have not selected rural areas for practice, with only approximately 8% ofemergency physicians practicing in rural areas,6 it is likely that given the opportunities present and perceivedsaturation in many non-rural settings, more EM graduates will pursue practice in a rural setting. With thesechanging practice dynamics in mind, this simulation provides the opportunity for residents and medicalstudents to experience the management of a STEMI in the rural setting, with a focus upon the indications,contraindications, dosing, and disposition of a patient receiving thrombolytics.Educational Objectives: By the end of this simulation, learners will be able to:1. Diagnose ST elevation myocardial infarction accurately and initiate thrombolysis in the rural settingwithout timely access to cardiac catheterization.2. Engage the simulated patient in a shared decision-making conversation, clearly outlying the benefitsand risks of thrombolysis.3. Identify the indications and contraindications for thrombolysis in ST elevation myocardial infarction.4. Arrange for transfer to a tertiary care center following completion of thrombolysis.Educational Methods: This scenario is a simulated encounter in a rural emergency department settingrequiring the diagnosis of a STEMI, a discussion with the patient regarding the risks and benefits ofthrombolysis prior to administration, administration of thrombolysis, and transfer of patient to a higher levelof care.Research Methods: The educational content of this simulation as a teaching instrument was evaluated bythe learner utilizing an internally developed survey after case completion. This survey was reviewed forprecision of language and assessment of learning objectives by our simulation faculty and other members ofour West Virginia University Emergency Medicine Department of Medical Education. The learner was askedto specify any prior experience with rural STEMI management as well as quantify via a five-point Likert Scale,where 1 = very uncomfortable and 5 = very comfortable, their level of comfort with thrombolysis before andafter the scenario as well as their comfort with having a shared decision-making conversation with patientswith regards to thrombolysis. Learners were also asked to rank the helpfulness of this simulation in preparingthem for administering thrombolytics for STEMI in a rural setting on a five-point Likert scale, where 1 = nothelpful and 5 =very helpful. An open response section was also provided to allow learners the opportunity tocomment directly on any aspect of the simulation.Results: Data was collected anonymously from 16 PGY1-3 resident learners via surveys with a 100% responserate. Overall, the feedback received regarding the simulation was positive. There was a low average comfortlevel with administering thrombolytics and having a shared decision-making conversation regardingadministering thrombolytics. There was a high average rating of the helpfulness of this simulation in preparing residents for this conversation as well as managing STEMIs in a rural setting. Subjective commentsregarding the simulation were universally positive.Discussion: The management of STEMI in the rural emergency department differs significantly from theenvironment in which many EM residents train. As a leading cause of death in the United States, STEMImanagement is a vital component of EM resident education. Although the concept of thrombolysis in the rural setting is discussed, the opportunity for real-world experience in its execution is often limited despitemany graduates ultimately working in rural emergency departments. This simulation sought to provide arealistic patient encounter to promote familiarity and comfort in the identification, patient discussion andexecution of thrombolysis in the treatment of a STEMI. The educational content was shown to be effectivevia learner survey completion.

This paper presents software for calculating the optimal mass of samples with complex compositions (e.g. supported metal catalysts) for X-ray absorption spectroscopy (XAS) and scattering measurements. The ability to calculate the sample mass and other relevant parameters needed for an XAS measurement allows experimentalists to be better prepared in terms of detector selection, energy range of scan and overall time needed to complete the measurement, thus increasing efficiency. CatMass builds on existing sample mass calculators allowing users to determine the optimum sample preparation, collection geometry, usable energy range for a scan and approximate edge step of the absorption event. Visualization tools present the absorption calculation results in a format familiar to XAS experimentalists, with the added ability to save calculations and plots for future reference or recalculation. CatMass is a program broadly applicable in catalysis and is helpful for users with complex samples due to composition/stoichiometry or multiple competing elements.

Science, technology, engineering, and math (STEM) workers need both motivation and interpersonal skills in STEM disciplines. The aims of the study were to identify clusters of adolescents who vary in math and science motivation and interpersonal skills and to explore what factors are related to membership in a high math and science motivation and interpersonal skills cluster. Participants included 467 adolescents (312 female; M[subscript age] = 15.12 to SD = 1.71 year) recruited from out-of-school STEM programs in the US and UK. Findings from latent class analyses revealed four clusters, including a "High Math and Science Motivation and Interpersonal Skills" group, as well as groups that exhibited lower levels of either motivation or interpersonal skills. STEM program belonging, and STEM identity are related to membership in the high motivation and skills cluster. Findings provide insight into factors that may encourage motivation and interpersonal skills in adolescents, preparing them for STEM workforce entry.

Single atoms of platinum group metals on CeO2 represent a potential approach to lower precious metal requirements for automobile exhaust treatment catalysts. Here we show the dynamic evolution of two types of single-atom Pt (Pt1) on CeO2, i.e., adsorbed Pt1 in Pt/CeO2 and square planar Pt1 in PtATCeO2, fabricated at 500 °C and by atom-trapping method at 800 °C, respectively. Adsorbed Pt1 in Pt/CeO2 is mobile with the in situ formation of few-atom Pt clusters during CO oxidation, contributing to high reactivity with near-zero reaction order in CO. In contrast, square planar Pt1 in PtATCeO2 is strongly anchored to the support during CO oxidation leading to relatively low reactivity with a positive reaction order in CO. Reduction of both Pt/CeO2 and PtATCeO2 in CO transforms Pt1 to Pt nanoparticles. However, both catalysts retain the memory of their initial Pt1 state after reoxidative treatments, which illustrates the importance of the initial single-atom structure in practical applications.

Stable catalysts are essential to address energy and environmental challenges, especially for applications in harsh environments (for example, high temperature, oxidizing atmosphere and steam). In such conditions, supported metal catalysts deactivate due to sintering-a process where initially small nanoparticles grow into larger ones with reduced active surface area-but strategies to stabilize them can lead to decreased performance. Here we report stable catalysts prepared through the encapsulation of platinum nanoparticles inside an alumina framework, which was formed by depositing an alumina precursor within a separately prepared porous organic framework impregnated with platinum nanoparticles. These catalysts do not sinter at 800 °C in the presence of oxygen and steam, conditions in which conventional catalysts sinter to a large extent, while showing similar reaction rates. Extending this approach to Pd-Pt bimetallic catalysts led to the small particle size being maintained at temperatures as high as 1,100 °C in air and 10% steam. This strategy can be broadly applied to other metal and metal oxides for applications where sintering is a major cause of material deactivation.

In most Western countries, girls outperform boys in academic engagement, scholastic achievement, and school completion. In the current study, researchers assessed the developmental trajectories of European French and North African French boys' (N = 549; M[subscript age] = 11.9 years) perceptions of girls' and boys' ability to succeed in school. Boys reported their perceptions of the academic aptitude of boys and girls annually across the four years of French middle school. Results indicated that both ethnic groups perceived girls to have greater school aptitude than boys in Grade 6, with a larger difference among European French than North African French boys. Boys' perceptions of the school aptitude of boys declined over the four years among both groups, with no ethnic differences in the size of pro-female bias by Grade 9. Implications are considered for developmental theory, including the importance of cultural beliefs that youth experience in the home and school settings.

Identity development is theorized to be a cornerstone of adolescence. An abundance of evidence has documented the significance of specific social identities (e.g., ethnic-racial or sexual identity) in the adjustment of adolescents. Research has found that youth who have explored their social identities and have more positive views of their social groups are likely to adjust more successfully across many developmental outcomes. Given evidence documenting the importance of social identities, in this article, we argue that identities should be leveraged to promote positive adjustment, particularly among youth experiencing marginalization. We present a theoretically driven rationale for why social identities should be considered assets that provide opportunities for intervention to improve youth's lives. We also describe two interventions that efficaciously targeted social identity development and demonstrated positive effects on adjustment. We close with directions for research and implementation and a call to invest in this important work.

Graphene is a novel material with extraordinary promise in various nano-based applications, including increases in strength, conductivity, filtration, and electrical capacity. Graphene can be synthesized and tested in a wide variety of applications in secondary or undergraduate settings. Allowing students to choose their own application and method of testing the graphene they synthesize is an engaging and authentic project based on engineering design and grounded in the tenets of constructivism. One of the many possible applications, reinforcement of paper mache by graphene, is easily adapted, uses familiar materials and methods, is cheap, and is easy to test. This student-centered project has led to increases in student content knowledge and lab skills. It increases students' confidence in designing their own solutions, analyzing data, and using scientific inquiry and engineering design.

Atomically dispersed metals on metal oxide supports are a rapidly growing class of catalysts. Developing an understanding of where and how the metals are bonded to the supports is challenging because support surfaces are heterogeneous, and most reports lack a detailed consideration of these points. Herein, we report two atomically dispersed CO oxidation catalysts having markedly different metal-support interactions: platinum in the first layer of crystalline MgO powder and platinum in the second layer of this support. Structural models have been determined on the basis of data and computations, including those determined by extended X-ray absorption fine structure and X-ray absorption near edge structure spectroscopies, infrared spectroscopy of adsorbed CO, and scanning transmission electron microscopy. The data demonstrate the transformation of surface to subsurface platinum as the temperature of sample calcination increased. Catalyst performance data demonstrate the lower activity but greater stability of the subsurface platinum than of the surface platinum.

Ethnically and racially diverse schools provide students opportunities to socially interact with both same- and cross-ethnic peers that can shape their sense of belonging within a school. This study investigates the extent to which same- or cross-ethnic friends influence feelings of school belonging in two large, diverse U.S. high schools (total N = 4,461; 9th-12th grade; 49.6% girls). Employing a longitudinal social network analytic approach, using stochastic actor-oriented modeling, this study found that students become more similar or stay similar to their same-ethnic friends, but not cross-ethnic friends, with no clear indication that students select friends based on similar levels of belonging. These novel findings highlight how feelings of school belonging are fostered through sociability in same-ethnic friend groups. Implications for interventions and other approaches to enhance school belonging are discussed.

The conversion of CO2 into fuels and chemicals is an attractive option for mitigating CO2 emissions. Controlling the selectivity of this process is beneficial to produce desirable liquid fuels, but C-C coupling is a limiting step in the reaction that requires high pressures. Here, we propose a strategy to favor C-C coupling on a supported Ru/TiO2 catalyst by encapsulating it within the polymer layers of an imine-based porous organic polymer that controls its selectivity. Such polymer confinement modifies the CO2 hydrogenation behavior of the Ru surface, significantly enhancing the C2+ production turnover frequency by 10-fold. We demonstrate that the polymer layers affect the adsorption of reactants and intermediates while being stable under the demanding reaction conditions. Our findings highlight the promising opportunity of using polymer/metal interfaces for the rational engineering of active sites and as a general tool for controlling selective transformations in supported catalyst systems.

Elucidation of reaction mechanisms and the geometric and electronic structure of the active sites themselves is a challenging, yet essential task in the design of new heterogeneous catalysts. Such investigations are best implemented via a multipronged approach that comprises ambient pressure catalysis, surface science, and theory. Herein, we employ this strategy to understand the workings of NiAu single-atom alloy (SAA) catalysts for the selective nonoxidative dehydrogenation of ethanol to acetaldehyde and hydrogen. The atomic dispersion of Ni is paramount for selective ethanol to acetaldehyde conversion, and we show that even the presence of small Ni ensembles in the Au surface results in the formation of undesirable byproducts via C-C scission. Spectroscopic, kinetic, and theoretical investigations of the reaction mechanism reveal that both C-H and O-H bond cleavage steps are kinetically relevant and single Ni atoms are confirmed as the active sites. X-ray absorption spectroscopy studies allow us to follow the charge of the Ni atoms in the Au host before, under, and after a reaction cycle. Specifically, in the pristine state the Ni atoms carry a partial positive charge that increases upon coordination to the electronegative oxygen in ethanol and decreases upon desorption. This type of oxidation state cycling during reaction is similar to the behavior of single-site homogeneous catalysts. Given the unique electronic structure of many single-site catalysts, such a combined approach in which the atomic-scale catalyst structure and charge state of the single atom dopant can be monitored as a function of its reactive environment is a key step toward developing structure-function relationships that inform the design of new catalysts.

Compositionally versatile, nonstoichiometric, mixed ionic-electronic conducting metal oxides of the form A n+1B n O3n+1 (n = 1 → ∞; A = rare-earth-/alkaline-earth-metal cation; B = transition-metal (TM) cation) remain a highly attractive class of electrocatalysts for catalyzing the energy-intensive oxygen evolution reaction (OER). The current design strategies for describing their OER activities are largely derived assuming a static, unchanged view of their surfaces, despite reports of dynamic structural changes to 3d TM-based perovskites during OER. Herein, through variations in the A- and B-site compositions of A n+1B n O3n+1 oxides (n = 1 (A2BO4) or n = ∞ (ABO3); A = La, Sr, Ca; B = Mn, Fe, Co, Ni), we show that, in the absence of electrolyte impurities, surface restructuring is universally the source of high OER activity in these oxides and is dependent on the initial oxide composition. Oxide surface restructuring is induced by irreversible A-site cation dissolution, resulting in in situ formation of a TM oxyhydroxide shell on top of the parent oxide core that serves as the active surface for OER. The rate of surface restructuring is found to depend on (i) composition of A-site cations, with alkaline-earth-metal cations dominating lanthanide cation dissolution, (ii) oxide crystal phase, with n = 1 A2BO4 oxides exhibiting higher rates of A-site dissolution in comparison to n = ∞ ABO3 perovskites, (iii) lattice strain in the oxide induced by mixed rare-earth- and alkaline-earth-metal cations in the A-site, and (iv) oxide reducibility. Among the in situ generated 3d TM oxyhydroxide structures from A n+1B n O3n+1 oxides, Co-based structures are characterized by superior OER activity and stability, even in comparison to as-synthesized Co-oxyhydroxide, pointing to the generation of high active surface area structures through oxide restructuring. These insights are critical toward the development of revised design criteria to include surface dynamics for effectively describing the OER activity of nonstoichiometric mixed-metal oxides.

Atomically dispersed noble metal catalysts have drawn wide attention as candidates to replace supported metal clusters and metal nanoparticles. Atomic dispersion can offer unique chemical properties as well as maximum utilization of the expensive metals. Addition of a second metal has been found to help reduce the size of Pt ensembles in bimetallic clusters; however, the stabilization of isolated Pt atoms in small nests of nonprecious metal atoms remains challenging. We now report a novel strategy for the design, synthesis, and characterization of a zeolite-supported propane dehydrogenation catalyst that incorporates predominantly isolated Pt atoms stably bonded within nests of Zn atoms located within the nanoscale pores of dealuminated zeolite Beta. The catalyst is stable in long-term operation and exhibits high activity and high selectivity to propene. Atomic resolution images, bolstered by X-ray absorption spectra, demonstrate predominantly atomic dispersion of the Pt in the nests and, with complementary infrared and nuclear magnetic resonance spectra, determine a structural model of the nested Pt.

Electronic and geometric interactions between active and support phases are critical in determining the activity of heterogeneous catalysts, but metal-support interactions are challenging to study. Here, it is demonstrated how the combination of the monolayer-controlled formation using atomic layer deposition (ALD) and colloidal nanocrystal synthesis methods leads to catalysts with sub-nanometer precision of active and support phases, thus allowing for the study of the metal-support interactions in detail. The use of this approach in developing a fundamental understanding of support effects in Pd-catalyzed methane combustion is demonstrated. Uniform Pd nanocrystals are deposited onto Al2 O3 /SiO2 spherical supports prepared with control over morphology and Al2 O3 layer thicknesses ranging from sub-monolayer to a ≈4 nm thick uniform coating. Dramatic changes in catalytic activity depending on the coverage and structure of Al2 O3 situated at the Pd/Al2 O3 interface are observed, with even a single monolayer of alumina contributing an order of magnitude increase in reaction rate. By building the Pd/Al2 O3 interface up layer-by-layer and using uniform Pd nanocrystals, this work demonstrates the importance of controlled and tunable materials in determining metal-support interactions and catalyst activity.

Single-atom catalysts (SACs) often exhibit dynamic responses to the reaction and pretreatment environment that affect their activity. The lack of understanding of these behaviors hinders the development of effective, stable SACs, and makes their investigations rather difficult. Here we report a reduction-oxidation cycle that induces nearly 5-fold activity enhancement on Pt/TiO2 SACs for the reverse water-gas shift (rWGS) reaction. We combine microscopy (STEM) and spectroscopy (XAS and IR) studies with kinetic measurements, to convincingly show that the low activity on the fresh SAC is a result of limited accessibility of Pt single atoms (Pt1) due to high Pt-O coordination. The reduction step mobilizes Pt1, forming small, amorphous, and unstable Pt aggregates. The reoxidation step redisperses Pt into Pt1, but in a new, less O-coordinated chemical environment that makes the single metal atoms more accessible and, consequently, more active. After the cycle, the SAC exhibits superior rWGS activity to nonatomically dispersed Pt/TiO2. During the rWGS, the activated Pt1 experience slow deactivation, but can be reactivated by mild oxidation. This work demonstrates a clear picture of how the structural evolution of Pt/TiO2 SACs leads to ultimate catalytic efficiency, offering desired understanding on the rarely explored dynamic chemical environment of supported single metal atoms and its catalytic consequences.

The atomic scale structure of the active sites in heterogeneous catalysts is central to their reactivity and selectivity. Therefore, understanding active site stability and evolution under different reaction conditions is key to the design of efficient and robust catalysts. Herein we describe theoretical calculations which predict that carbon monoxide can be used to stabilize different active site geometries in bimetallic alloys and then demonstrate experimentally that the same PdAu bimetallic catalyst can be transitioned between a single-atom alloy and a Pd cluster phase. Each state of the catalyst exhibits distinct selectivity for the dehydrogenation of ethanol reaction with the single-atom alloy phase exhibiting high selectivity to acetaldehyde and hydrogen versus a range of products from Pd clusters. First-principles based Monte Carlo calculations explain the origin of this active site ensemble size tuning effect, and this work serves as a demonstration of what should be a general phenomenon that enables in situ control over catalyst selectivity.

Operando X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD) were performed on a Co/TiO2 Fischer-Tropsch synthesis (FTS) catalyst at 16 bar for (at least) 48 h time-on-stream in both a synchrotron facility and a laboratory-based X-ray diffractometer. Cobalt carbide formation was observed earlier during FTS with operando XAS than with XRD. This apparent discrepancy is due to the higher sensitivity of XAS to a short-range order. Interestingly, in both cases, the product formation does not noticeably change when cobalt carbide formation is detected. This suggests that cobalt carbide formation is not a major deactivation mechanism, as is often suggested for FTS. Moreover, no cobalt oxide formation was detected by XAS or XRD. In other words, one of the classical proposals invoked to explain Co/TiO2 catalyst deactivation could not be supported by our operando X-ray characterization data obtained at close to industrially relevant reaction conditions. Furthermore, a bimodal cobalt particle distribution was observed by high-angle annular dark-field scanning transmission electron microscopy and energy-dispersive X-ray analysis, while product formation remained relatively stable. The bimodal distribution is most probably due to the mobility and migration of the cobalt nanoparticles during FTS conditions.

Although Cu/ZnO-based catalysts have been long used for the hydrogenation of CO2 to methanol, open questions still remain regarding the role and the dynamic nature of the active sites formed at the metal-oxide interface. Here, we apply high-pressure operando spectroscopy methods to well-defined Cu and Cu0.7Zn0.3 nanoparticles supported on ZnO/Al2O3, γ-Al2O3 and SiO2 to correlate their structure, composition and catalytic performance. We obtain similar activity and methanol selectivity for Cu/ZnO/Al2O3 and CuZn/SiO2, but the methanol yield decreases with time on stream for the latter sample. Operando X-ray absorption spectroscopy data reveal the formation of reduced Zn species coexisting with ZnO on CuZn/SiO2. Near-ambient pressure X-ray photoelectron spectroscopy shows Zn surface segregation and the formation of a ZnO-rich shell on CuZn/SiO2. In this work we demonstrate the beneficial effect of Zn, even in diluted form, and highlight the influence of the oxide support and the Cu-Zn interface in the reactivity.

An understanding of the fundamentals of the reaction between CuO with trace amounts of H2S to form CuS products is critical for the optimal utilization of this process in sulfur removal applications. Unfortunately, CuS is a complex material, featuring various Cu2-xS compounds (with 0 ≤ x ≤ 1), distorted crystal phases, and varying electronic structures and coordination environments of Cu and S ions. In this work, we combine ex situ and in situ X-ray absorption spectroscopy (XAS) at S and Cu K edges, fixed bed sorption experiments, DFT simulations, and other characterization techniques to speciate the CuS products formed at different temperatures (298-383 K) and from CuO sorbents with different crystallite sizes (2.8-40 nm). The results of our analysis identify the formation of a distorted CuS layer at the surface of CuO crystals with disulfide groups with shorter Cu-S bonds and higher delocalization of the positive charge of the Cu center into (S1-)2. This distorted CuS layer dominates the XAS signal at lower temperatures (298-323 K) and at the initial stages of sulfidation at higher temperatures (353 and 383 K) where conversion is low (

Youth victimization and aggression are common in adolescents' everday lives. This study examines relations between youth cognition and reasoning around bullying and possible responses to bullying, peer nominations related to youth roles in the bullying ecology and self-report experiences of perceived racial discrimination using latent class analyses. Participants included 6th (n = 423) and 9th (n = 392) grade adolescents in the United States (49.1% female). Five distinct classes emerged: Typical, Uninvolved, Challengers, Experiences Discrimination, and Experiences Discrimination and Involved. Furthermore, participants in these classes reasoned about the acceptability of youth aggression and about their likelihood of different responses to youth aggression in distinct ways. Findings document that the Challengers class was most likely to judge the aggression as wrong and the least likely to indicate that they would not respond if they observed aggression. Furthermore, both classes of youth who reported experiencing discrimination judged the aggression as more acceptable.

Earth's critical zone (CZ) is the uppermost layer of Earth's continents, which supports ecosystems and humans alike. CZ science aims to understand how interactions among rock, soil, water, air, and terrestrial organisms influence Earth as a habitable system. Thus, CZ science provides the framework for a holistic-systems approach to teaching Earth surface and environmental science, especially related to environmental sustainability. Here, we describe efforts by an interdisciplinary team to create a full-semester, university curriculum that introduces upper-division students to CZ science. Course topics include a background in CZ science, key concepts and methods of CZ science, and units on land-atmosphere interactions, water budgets, landscape evolution, and biogeochemistry. The course culminates with a unit on human interactions within the CZ. Through interactive activities that use data sets from U.S. CZ observatories, the course emphasizes how a CZ framework is appropriate for teaching concepts across scientific disciplines, concepts of environmental sustainability, and the usefulness of CZ science for considering humanity's grand challenges. Materials can be integrated into existing courses or used as an independent course to maximize instructor flexibility; all materials were piloted in eight separate courses across a range of university settings. Although preassessments and postassessments of geoscience literacy did not show much change, students overwhelmingly agreed that they could use what they learned to help society overcome grand challenges. Thus, the holistic-systems approach advocated by CZ science and explored throughout this curriculum provides a unique opportunity to engage students in thinking about complex issues related to environmental sustainability.

Single-site Ir(CO)2 complexes bonded to high-surface-area metal oxide supports, SiO2, TiO2, Fe2O3, CeO2, MgO, and La2O3, were synthesized by chemisorption of Ir(CO)2(acac) (acac = acetylacetonate) followed by coating with each of the following ionic liquids (ILs): 1-n-butyl-3-methylimidazolium tetrafluoroborate, [BMIM][BF4], 1-n-butyl-3-methylimidazolium acetate, [BMIM][Ac], and 1-(3-cyanopropyl)-3-methylimidazolium dicyanamide, [CPMIM][DCA]. Extended X-ray absorption fine structure spectroscopy showed that site-isolated iridium was bonded to oxygen atoms of the support. Electron densities on the iridium enveloped by each IL sheath/support combination were characterized by carbonyl infrared spectroscopy of the iridium gem-dicarbonyls and by X-ray absorption near-edge structure data. The electron-donor/acceptor tendencies of both the support and IL determine the activity and selectivity of the catalysts for the hydrogenation of 1,3-butadiene, with electron-rich iridium being selective for partial hydrogenation. The results resolve the effects of the IL and support as ligands; for example, the effect of the IL becomes dominant when the support has a weak electron-donor character. The combined effects of supports and ILs as ligands offer broad opportunities for tuning catalytic properties of supported metal catalysts.

We examined developmental changes in self-esteem from late childhood to late adolescence in African American girls (N = 124), comparing skin tone groups. Girls completed a measure of self-esteem when they were in Grades 5, 7, 10, and 12, and in Grade 12 their skin tone was rated on a 3-point scale (1 = "Light," 2 = "Medium," 3 = "Dark"). Girls with lighter skin reported higher self-esteem than dark and medium-toned girls in Grades 5 and 7, and their self-esteem remained high across the seven years of the study. The self-esteem of dark- and medium-skinned girls increased in high school such that at Grade 12, medium-skinned girls had higher self-esteem than dark-skinned girls, who did not differ from light-skinned girls. The results are discussed in terms of theory-building on the topic of colorism.

A focus on positive child development among Indigenous children has largely been absent from developmental science. In this special section of Child Development, we sought to address continuing inequity in representation and valuing Indigenous knowledge and voices by soliciting articles that identified cultural and strengths‐based factors Indigenous children, youth, and families cultivate and leverage to promote positive development. In this introduction to the special section, we provide an overview of the four empirical articles included, with attention to the ways these articles advance Indigenous paradigms and methodologies by focusing on the unique histories and strengths of four distinct Indigenous communities. We end with a discussion of how to promote continued growth and inclusiveness in developmental science with Indigenous communities. [ABSTRACT FROM AUTHOR]

Multicomponent catalysts can be designed to synergistically combine reaction intermediates at interfacial active sites, but restructuring makes systematic control and understanding of such dynamics challenging. We here unveil how reducibility and mobility of indium oxide species in Ru‐based catalysts crucially control the direct, selective conversion of CO2 to ethanol. When uncontrolled, reduced indium oxide species occupy the Ru surface, leading to deactivation. With the addition of steam as a mild oxidant and using porous polymer layers to control In mobility, Ru−In2O3 interface sites are stabilized, and ethanol can be produced with superior overall selectivity (70 %, rest CO). Our work highlights how engineering of bifunctional active ensembles enables cooperativity and synergy at tailored interfaces, which unlocks unprecedented performance in heterogeneous catalysts. [ABSTRACT FROM AUTHOR]

Given the importance of self-esteem for promoting adolescents' social, psychological, and academic adjustment and the growing importance of social identities during adolescence, this five-wave study examined whether an identity-based self-affirmation intervention attenuated declines in adolescent self-esteem following the high school transition. A sample of ninth graders in the United States (N = 388; Mage = 14.05; 60.6% female; 35.8% male; 3.6% nonbinary, trans, or identifying with another gender; 46% White, 19% Black, 17% Asian, 6% Arab, Middle Eastern, North African, 6% Biracial/Multiethnic, 3% Latinx/Hispanic, and 3% another race/ethnicity) was recruited for the study. Following completion of a baseline online survey assessing self-esteem, participants were assigned to one of three conditions and corresponding writing exercises: identity-based self-affirmation, values-based self-affirmation, or control. Participants completed the same writing exercise during the first three waves of the study, and they completed measures of self-esteem at all five waves. Results indicated that participants in the self-affirmation conditions, but not the control condition, were protected from declining self-esteem across 1 year. Public Significance Statement: Self-esteem is a psychological phenomenon that predicts a host of important outcomes for youth but typically stagnates or even declines during adolescence. The present study developed an identity-based and values-based self-affirmation intervention to mitigate declines in ninth graders' self-esteem across 1 year. Results revealed that adolescents in the control condition exhibited declines in self-esteem, whereas those in the identity-based or values-based self-affirmation conditions were buffered from deteriorating self-esteem. The findings suggest that providing adolescents with opportunities to reflect on values and social identities of personal importance could have cascading effects on psychological adjustment following the high school transition. [ABSTRACT FROM AUTHOR]