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We compare the preferences of athletes who practice individual sports to those of non-athletes, by combining incentivized tasks and survey questions. Athletes were more likely to opt for the tournament payment scheme in the competitive tasks. Female athletes and male non-athletes were equally likely to select the tournament payment. We also find that female athletes were equally as risk-tolerant as non-athlete men and equally as risk-tolerant as men overall (whether athletes or non-athletes), for incentivized tasks and stated preferences. It is concluded that participation in competitive sports favors closure of the gender gaps in competitiveness and risk tolerance.

In situ Mo K-edge X-ray absorption spectroscopy reveals different carburization pathways for unsupported and supported MoO3 yielding Mo2C and Mo2C/SiO2. Mo2C/SiO2 features higher resistance to oxidation under dry reforming of methane than Mo2C.

Platinum nanoparticles (NPs) supported by titania exhibit a strong metal-support interaction (SMSI)[1] that can induce overlayer formation and encapsulation of the NP's with a thin layer of support material. This encapsulation modifies the catalyst's properties, such as increasing its chemoselectivity[2] and stabilizing it against sintering.[3] Encapsulation is typically induced during high-temperature reductive activation and can be reversed through oxidative treatments.[1] However, recent findings indicate that the overlayer can be stable in oxygen.[4, 5] Using in situ transmission electron microscopy, we investigated how the overlayer changes with varying conditions. We found that exposure to oxygen below 400 °C caused disorder and removal of the overlayer upon subsequent hydrogen treatment. In contrast, elevating the temperature to 900 °C while maintaining the oxygen atmosphere preserved the overlayer, preventing platinum evaporation when exposed to oxygen. Our findings demonstrate how different treatments can influence the stability of nanoparticles with or without titania overlayers. expanding the concept of SMSI and enabling noble metal catalysts to operate in harsh environments without evaporation associated losses during burn-off cycling., Angewandte Chemie. International Edition, 62 (27), ISSN:1433-7851, ISSN:1521-3773, ISSN:0570-0833

International audience; Dilemmas related to the use of environmental resources concern diverse populations at local or global scales. Frequently, individuals are unable to visualize the consequences of their actions, where they belong in the decision-making line, and have no information about past choices or the time horizon. We design a new one-shot extraction game to capture these dynamic decisions. We present results from a nationwide common pool resource experiment, conducted simultaneously in eleven French cities, involving a total of 2813 participants. We examine, for the first time, the simultaneous impact of several variables on the amount of resource extracted: the local vs. the national scale of the resource, the size of the group (small vs. big), the low vs. high recovery rate of the resource, and the available information. We show that individuals significantly reduce extraction levels in local as compared to national level dilemmas and that providing recommendations on sustainable extraction amounts significantly improves the sustainability of the resource. Overall, women extract significantly less, but care more about preserving the local resource; older participants extract significantly more resources but extract less from the national resource. Our experiment also fulfills a science popularization pedagogical aim, which we discuss..

International audience; Recent empirical research in accounting and finance shows that the magnitudeof stock prices influences analysts’ price forecasts (Roger, Roger et Schatt [2018]).In this paper, we report the results of a novel experiment where some subjects areasked to forecast future prices in a continuous double auction market. In this expe-riment, two successive markets take place: one where the fundamental value is asmall price and one where the fundamental value is a large price. Although marketprices are higher (compared to fundamental value) in small price markets than inlarge price markets, our results indicate that analyst subjects’ forecasts are moreoptimistic in small price markets compared to large price markets. Analyst subjectsstrongly anchor on past price trends when building their price forecasts and donot mitigate subject traders’ bias. Overall, our experimental findings support theexistence of a small price bias deeply rooted in the human brain.; La littérature récente en comptabilité et en finance montre que le niveau des cours des actions influence les prévisions de prix des analystes (Roger, Roger et Schatt [2018]). Dans le présent article, nous montrons que ce résultat reste valide dans le cadre contrôlé du laboratoire quand des sujets doivent prévoir les prix futurs sur un marché expérimental auquel ils ne participent pas. Chaque sujet fait des prévisions lors de deux marchés successifs : l’un pour lequel la valeur fondamentale est faible et l’autre pour lequel la valeur fondamentale est élevée. Bien que les prix de marché soient plus élevés (par rapport à la valeur fondamentale) sur les marchés à petits prix du fait du biais de « petit prix » des sujets traders, nos résultats indiquent que les prévisions des analystes sont plus optimistes sur les marchés à petits prix que sur les marchés à prix élevés. Les sujets analystes ancrent leurs prévisions sur les prix de marché passés et n’atténuent pas le biais des sujets traders. Nos résultats montrent ainsi que l’existence de ce biais de « petit prix » reflète l’utilisation par les sujets de deux échelles mentales différentes pour traiter petits et grands nombres.

Masuda et al. (Games Econ Behav 83:73–85, 2014) showed that the minimum approval mechanism (AM) implements the efficient level of public good theoretically and experimentally in a linear public good game. We extent this result to a two-players common pool resource (CPR) game. The AM adds a second stage into the extraction game. In the first stage, each group member proposes his level of extraction. In the second stage, the proposed extractions and associated payoffs are displayed and each player is asked to approve or to disapprove both proposed extractions. If both players approve, the proposals are implemented. Otherwise, a uniform level of extraction, the disapproval benchmark (DB), is imposed onto each player. We consider three different DBs: the minimum proposal (MIN), the maximum proposal (MAX) and the Nash extraction level (NASH). We derive theoretical predictions for each DB following backward elimination of weakly dominated strategies (BEWDS). We first underline the strength of the AM, by showing that the MIN implements the optimum theoretically and experimentally. The sub-games predicted under the NASH are Pareto improving with respect to the Nash equilibrium. The MAX leads, either to Pareto improving outcomes with respect to the free access extractions, or to a Pareto degradation. Our experimental results show that the MAX and the NASH reduce the level of over-extraction of the CPR. The MAX leads above all to larger reductions of (proposed and realized) extractions than the NASH.

Les attendus d’une approche d’économie comportementale pour les décisions individuelles face à la pandémie de COVID-19 : succès et déceptions.Dans le cadre du premier appel à projet « Flash-COVID-19 » de l’Agence nationale de la recherche, nous avons mobilisé des méthodes récentes de l’économie comportementale afin de mieux comprendre les décisions des individus face à la crise sanitaire due à la pandémie de COVID-19 (coronavirus disease 2019) et d’identifier les paramètres pouvant influencer le respect des mesures sanitaires. Cet article introduit brièvement l’économie comportementale, présente un compte rendu des attendus du projet CONFINOBS (Observance et observation des mesures barrières et du confinement : une approche d’économie comportementale) et de ses méthodes, puis il propose une synthèse des résultats obtenus.

International audience; We test the effectiveness of a social comparison nudge to enhance lockdown compliance during the Covid-19 pandemic, using a representative sampleof metropolitan French adultpopulation(N=1154). Respondents were randomly assigned to a favourable/unfavourable informational feedback (daily road traffic mobility patterns, in Normandy -a region of France) on peer lockdown compliance.Our dependent variable was the intention to comply with a possible future lockdown. We controlled for risk, time, and social preferences and tested the effectiveness of the nudge. We found no evidence of theeffectiveness of thesocial comparison nudge among the wholepopulation, butthe nudgewas effective when its recipient and the reference population shared the same geographical location(Normandy). Exploratory results on this subsample (N=52) suggest that this effectiveness could be driven by non-cooperative individuals.

Heterogeneous catalysts in the form of atomically dispersed metals on a support provide the most efficient utilization of the active component, which is especially important for scarce and expensive late transition metals. These catalysts also enable unique opportunities to understand reaction pathways through detailed spectroscopic and computational studies. Here, we demonstrate that atomically dispersed iridium sites on indium tin oxide prepared via surface organometallic chemistry display exemplary catalytic activity in one of the most challenging electrochemical processes, the oxygen evolution reaction (OER). In situ X-ray absorption studies revealed the formation of Ir-V=O intermediate under OER conditions with an Ir-O distance of 1.83 angstrom. Modeling of the reaction mechanism indicates that Ir-V=O is likely a catalyst resting state, which is subsequently oxidized to Ir-VI enabling fast water nucleophilic attack and oxygen evolution. We anticipate that the applied strategy can be instrumental in preparing and studying a broad range of atomically dispersed transition metal catalysts on conductive oxides for (photo) electrochemical applications., ACS Central Science, 6 (7), ISSN:2374-7951

National audience; This article provides a formal model of the value creation-appropriation dilemma in coopetition for innovation, that is, alliances among competing firms. The model determines the levels of cooperation that maximize the profit of each firm in an innovative coopetition agree¬ment regardless of the number of firms and their respective budget endowments dedicated to the coopetitive project. We answer the following questions: within an innovative coopetition agreement, will the partners cooperate more or less when their budget endowments change? What is the impact on profit? When is it profitable to accept a new partner into the agreement? What happens to the remaining firms when a partner withdraws from the agreement? We show that when the coopetitive budget of the focal firm increases, the focal firm allocates a larger part of this budget to value creation activities and increases its profit. In contrast, when a partnering firm increases its coopetitive budget, the focal firm reduces its budget for value creation activities to maintain a sufficient budget for value appropriation activities. We also show that the addition of a competitor with a large coopetitive budget to the innovative coopetition agreement decreases the cooperation of the focal firm but increases the profit of the initial partnering firms. In contrast, the exit of a partnering firm with a large coopetitive budget from the agreement intensifies the cooperation among the remaining firms but reduces their profit. competing firms. The model determines the levels of cooperation that maximize the profit of each firm in an innovative coopetition agreementregardless of the number of firms and their respective budget endowments dedicated to the coopetitive project. We answer thefollowing questions: within an innovative coopetition agreement, will the partners cooperate more or less when their budget endowmentschange? What is the impact on profit? When is it profitable to accept a new partner into the agreement? What happens to the remainingfirms when a partner withdraws from the agreement? We show that when the coopetitive budget of the focal firm increases, the focal firmallocates a larger part of this budget to value creation activities and increases its profit. In contrast, when a partnering firm increases itscoopetitive budget, the focal firm reduces its budget for value creation activities to maintain a sufficient budget for value appropriationactivities. We also show that the addition of a competitor with a large coopetitive budget to the innovative coopetition agreementdecreases the cooperation of the focal firm but increases the profit of the initial partnering firms. In contrast, the exit of a partnering firmwith a large coopetitive budget from the agreement intensifies the cooperation among the remaining firms but reduces their profit.

This paper investigates the relationship between mindfulness and well-being within the context of compliance with prophylactic measures in the time of COVID-19. We conducted a large-scale survey among a representative sample of the French population. We measured mindfulness, using the Mindful Attention Awareness Scale, and the extent to which respondents were impacted by COVID-19 in terms of their mood and quality of sleep, as well as how they complied with prophylactic measures. Our results suggest that more mindful individuals were less negatively impacted by COVID-19 with regard to their sleep and mood. Concerning the prophylactic measures, we obtained mixed results: more mindful participants were more likely to respect lockdowns, physical distancing and to cough in their sleeves, but did not wash their hands, wear masks or avoid touching their face more often than less mindful individuals.

The properties of two-dimensional (2D) van der Waals (vdW) materials can be tuned through nanostructuring or controlled layer stacking, where interlayer hybridization induces exotic electronic states and transport phenomena. Here, we describe an assisted self-assembly of twisted layer graphene. The process, which can be implemented in standard chemical vapour deposition (CVD) growth, is best described using the analogy to Origami and Kirigami of paper and involves wrinkle formation, folding, tearing, and re-growth. Inherent to the process is the formation of intertwined graphene spirals and conversion of the chiral angle of one-dimensional (1D) wrinkles into a 2D twist angle of a three-dimensional (3D) superlattice. The approach can be extended to other foldable 2D materials and facilitates the production of miniaturized electronic components, including capacitors, resistors, inductors, and super-conductors.

Graphene nanoribbons (GNRs) are considered one of the most promising materials for next generation electronics, however a reliable and controllable synthesis method is still lacking. Here, we report the CVD growth of GNRs on a copper surface and the corresponding mechanisms of growth. One-dimensional GNR growth is enabled by a vapor-liquid-solid (VLS) graphene growth guided by on-surface propagation of a liquid catalyst particle. Controlling the suppression of vapor-solid-solid (VSS) graphene growth along the width direction of the GNR by tuning the flow of H2 during growth gives rise to a spear head-shaped graphene that we term graphene nanospears (GNSs). The real-time visual and spatially resolved observations confirm the VSS growth of graphene can be fully suppressed and lead to GNR formation on Cu surface. These findings reveal key insight into the growth mechanism of graphene and open a door for achieving a facile and scalable method of synthesizing free standing GNRs.

We replicate Bocquého et al. (2014), who used multiple price lists to investigate the risk preferences of 107 French farmers. We collected new data from 1430 participants in 11 European farming systems. In agreement with the original study, farmers' risk preferences are best described by Cumulative Prospect Theory. Structural model estimates show that farmers in the new samples are, on average, less loss averse and more susceptible to probability distortion than in the original study. Explorative analyses indicate differences between estimation approaches, as well as heterogeneity between and within samples. We discuss challenges in replications of economic experiments with farmers across farming contexts.

International audience; We show that the acuity of the Approximate Number System (ANS), a cognitive system that allows humans and many animal species to evaluate quantities without using exact calculations, is a strong predictor of subjects’ earnings in experimental markets. We measure ANS acuity with a bounded number line estimation (NLE) task and find that subjects who perform better on the NLE task, obtain higher earnings in a continuous double auction experimental market. We underline two channels through which high ANS acu- ity subjects achieve better performance: they are rewarded for offering liquidity and are faster at exploiting trading opportunities. We also show that, in a given market, the distribution of NLE scores influences mispricing. Our results are unchanged when we control for differences in trading intensity, risk aversion, background education or demographic characteristics.

International audience; The public acceptability of a policy is an important issue in democracies, in particular for anti-COVID-19 policies, which require the adherence of the population to be applicable and efficient. Discrete choice experiment (DCE) can help elicit preference ranking among various policies for the whole population and subgroups. Using a representative sample of the French population, we apply DCE methods to assess the acceptability of various anti-COVID-19 measures, separately and as a package. Owing to the methods, we determine the extent to which acceptability depends on personal characteristics: political orientation, health vulnerability, or age. The young population differs in terms of policy preferences and their claim for monetary compensation, suggesting a tailored policy for them. The paper provides key methodological tools based on microeconomic evaluation of individuals’ preferences for improving the design of public health policies.

International audience; We study experimentally the reaction of asset markets to fundamental value (FV) shocks. The pre-shock and post-shock FV are both constant, but after the shock the FV is either higher or lower than before. We compare treatments with expected shocks (the date and the magnitude are known in advance, but not the direction) to treatments with unexpected shocks (subjects only know that a shock may occur but are unaware of the date and the magnitude). We observe mispricing in markets without shocks and in markets with shocks. Shocks tend to reduce the post-shock price deviation and to increase the difference of opinions (DO), whatever the type of the shock (expected or unexpected) and its direction (upwards or downwards). In contrast to standard predictions, the larger DO after a shock is not accompanied by an increase in transaction volumes, but by sharp depression of share turnover.

Metal catalysts play an important role in industrial redox reactions. Although extensively studied, the state of these catalysts under operating conditions is largely unknown, and assignments of active sites remain speculative. Herein, an operando transmission electron microscopy study is presented, which interrelates the structural dynamics of redox metal catalysts to their activity. Using hydrogen oxidation on copper as an elementary redox reaction, it is revealed how the interaction between metal and the surrounding gas phase induces complex structural transformations and drives the system from a thermodynamic equilibrium toward a state controlled by the chemical dynamics. Direct imaging combined with the simultaneous detection of catalytic activity provides unparalleled structure–activity insights that identify distinct mechanisms for water formation and reveal the means by which the system self-adjusts to changes of the gas-phase chemical potential. Density functional theory calculations show that surface phase transitions are driven by chemical dynamics even when the system is far from a thermodynamic phase boundary. In a bottom-up approach, the dynamic behavior observed here for an elementary reaction is finally extended to more relevant redox reactions and other metal catalysts, which underlines the importance of chemical dynamics for the formation and constant re-generation of transient active sites during catalysis. ISSN:0935-9648 ISSN:1521-4095

We propose a five-player common-pool resource (CPR) game with endogenous coalition formation. We show that the level of extraction from the CPR depends on the size of each coalition that is formed and on the final coalition structure. These predictions are tested in a laboratory experiment. We consider two treatments: dictator vs. veto. In the dictator treatment, at each stage of the coalition formation game, a randomly chosen player imposes the coalition size and selected members cannot refuse to become a member. In the veto treatment, players have the right to refuse joining the current coalition if they want to and make counter-proposals. We observe that the formation of the grand coalition is more frequent in the dictator treatment. However, with the repetition of the coalition formation game, the grand coalition becomes more frequent under both treatment, and past experience of a grand coalition increases the likelihood that the current coalition structure is the grand coalition. Finally, the possibility to form coalitions is beneficial at reducing CPR extractions, compared to the singleton structure, in both treatments.

Synthesizing high-quality two-dimensional nanomaterials of non-layered metal oxide is a grand challenge because it requires long range single-crystallinity and clean high-energy surfaces. Here, we report the synthesis of single-crystalline MgO(111) nanosheets via a two-step process involving the formation of ultrathin Mg(OH)2 nanosheets as precursor and their selective topotactic conversion upon heating under dynamic vacuum. The defect-rich surface displays terminal -OH groups, 3-coordinated O2- sites, low-coordinated Mg2+ sites as well as single electrons trapped at oxygen vacancies, that render MgO nanosheets highly reactive as evidenced by the activation of CO molecules at low temperatures and pressures, with formation of strongly adsorbed red-shifted CO and coupling of CO molecules into C2 species.

Heterogeneous catalysts in the form of atomically dispersed metals on a support provide the most efficient utilization of the active component, which is especially important for scarce and expensive late transition metals. These catalysts also enable unique opportunities to understand reaction pathways through detailed spectroscopic and computational studies. Here we demonstrate that atomically dispersed iridium sites on indium tin oxide prepared via surface organometallic chemistry display exemplary catalytic activity in one of the most challenging electrochemical processes, oxygen evolution reaction (OER). In situ X-ray absorption studies revealed the formation of IrV=O intermediate under OER conditions with an Ir–O distance of 1.83 Å. Modelling of the reaction mechanism indicates that Ir(V)=O is likely a catalyst resting state, which is subsequently oxidized to Ir(VI) enabling fast water nucleophilic attack and oxygen evolution. We anticipate that the applied strategy can be instrumental in preparing and studying a broad range of atomically dispersed transition metal catalysts on conductive oxides for (photo)electrochemical applications.

Conventional finance models assume that stock price magnitude should not influence portfolio choices or future returns. This view is contradicted, however, by empirical evidence. In this paper, we show that trading prices, in experimental markets, are processed differently by participants depending on their magnitude. Our experiment has two consecutive treatments. One where the fundamental value is a small number (small price market) and one where the fundamental value is a large number (large price market). Small price markets exhibit greater mispricing than large price markets. We obtain this result both between-participants and within-participants. Our findings indicate that price magnitude has a direct impact on how individuals perceive the distribution of future returns. This result is at odds with standard finance theory but is consistent with: (1) evidence in neuropsychology on the use of different mental scales for small and large numbers, and (2) empirical results in the finance and accounting literature.

International audience; We study embezzlement when donations have to pass through intermediaries to reach recipients, by means of a sequential game tested in a laboratory experiment conducted in Tanzania. We investigate the impact on the amount embezzled of both the number of intermediaries in transfer chains and transparency about the donation. We show that donors are less generous in the presence of intermediaries. When transfer chains are shorter, aggregate embezzlement decreases, at least when donations are transparent. At the individual level, intermediaries embezzle less, the longer the transfer chain; this is due to less embezzlement at the beginning of the chain. We fail finding significant positive effects of transparency on the honesty of individual transfers through social judgment. JEL Codes: C91, D73, O19

Fluorine-containing bismuth vanadate (F:BiVO4) powder was synthesized using a new, clean, and simple solid-vapor reaction. Incorporation of fluorine mainly leads to the formation of cation vacancies. Electrodes were fabricated from the pre-synthesized powder samples by electrophoretic deposition onto fluorine-doped tin oxide coated glass slides and subsequent calcination. The photoelectrochemical performance concerning the water oxidation reaction was investigated and compared to pristine BiVO4 revealing strongly enhanced photoelectrochemical behavior for the F-containing BiVO4.

ZnO has prominent electron transport and optical properties, beneficial for photovoltaic application, but its surface is prone to the formation of defects. To overcome this problem, we deposited nanostructured TiO2 thin film on ZnO nanorods to form a stable shell. ZnO nanorods synthesized by wet-chemistry are single crystals. Three different procedures for deposition of TiO2 were applied. The influence of preparation methods and parameters on the structure, morphology, electrical and optical properties were studied. Nanostructured TiO2 shells show different morphologies dependent on deposition methods: (1) separated nanoparticles (by pulsed laser deposition (PLD) in Ar), (2) a layer with nonhomogeneous thickness (by PLD in vacuum or DC reactive magnetron sputtering), and (3) a homogenous thin layer along the nanorods (by chemical deposition). Based on the structural study, we chose the preparation parameters to obtain an anatase structure of the TiO2 shell. Impedance spectroscopy shows pure electron conductivity that was considerably better in all the ZnO@TiO2 than in bare ZnO nanorods or TiO2 layers. The best conductivity among the studied samples and the lowest activation energy was observed for the sample with a chemically deposited TiO2 shell. Higher transparency in the visible part of spectrum was achieved for the sample with a homogenous TiO2 layer along the nanorods, then in the samples with a layer of varying thickness.

Novel forms of black TiO2 nanotubes-based photocatalysts for water purification were prepared. Two features were combined: decoration of TiO2 nanotube arrays with Ag nanoparticles (sample TiO2-NT's@Ag) and further hydrogenation of this material (TiO2-NT's@Ag-HA). Obtained photocatalysts show high efficiency for degradation of salicylic acid, a typical water-borne pollutant. The photocatalysts considerably exceed the photocatalytic properties of TiO2 nanotubes and commercial TiO2 P25 taken as a reference for modeling of the photocatalytic process. The comparison of photocatalytic activities between novel photocatalyst was based on a numerical approach supported by the complex kinetic model. This model allowed a separate study of different contributions on overall degradation rate. The contributions include: salicylic acid photolysis, photocatalysis in UVB, UVA and in the visible part of applied simulated solar irradiation. The superior photocatalytic performance of the photocatalyst TiO2-NT's@Ag-HA, particularly under visible irradiation, was explained by the combined effect of a local surface plasmon resonance (LSPR) due to Ag nanoparticles and creation of additional energy levels in band-gap of TiO2 due to Ti3+ states at nanotube surfaces. The presence of Ag also positively influence charge separation of created electron-holes pairs. The synergy of several effects was quantified by a complex kinetic model through the factor of synergy, fSyn. Stability testing indicated that the catalysts were stable for at least 20 h. The novel design of catalysts, attached on Ti foils, presents a solid base for the development of more efficient photocatalytic reactors for large-scale with a long-term activity.

International audience; We study experimentally a two-stage common pool resource game. In the first stage, selected members of the group determine the level of protection for the resource. The protected fraction of the resource is equally shared among group members. In the second stage, the unprotected fraction of the resource is competed for. We consider three institutions varying in the extent by which subjects participate in the first stage: vote(all group members participate), dictator (only one member decides), and exogenous (no-one participates). We also vary the initial level of the resource: scarce or abundant. We establish the following results. First, we find that the voting institution provides more frequent protection and leads to higher protection levels than the dictatorial institution. In addition, higher protection tends to temper rent seeking for the unprotectedfraction of the resource for both institutions. Second, rent-seeking intensifies after a resource boom, but this effect is non-significant under the vote institution. Finally, rent-seeking is larger when the level of the resource is high, but this tendency is sharply reduced under the vote institution

Platinum and iridium polycrystalline foils were oxidized electrochemically through anodization to create thin platinum and iridium hydrous oxide layers, which were analyzed through laboratory photoelectron spectroscopy during heating and time series (temperature-programmed spectroscopy). The films contain oxygen in the form of bound oxides, water, and hydroxides and were investigated by depth profiling with high-energy photoelectron spectroscopy. The Pt films are unstable and begin to degrade immediately after removal from the electrolyte to form core–shell structures with a metallic inner core and a hydrous oxide outer shell almost devoid of Pt. However, evidence was found for metastable intermediate states of degradation; therefore, it may be possible to manufacture PtOx phases with increased stability. Heating the film to even 100 °C causes accelerated degradation, which shows that stoichiometric oxides such as PtO2 or PtO are not the active species in the electrolyte. The Ir films exhibit increased stability and higher surface Ir content, and gentle heating at low temperatures leads to a decrease in defect density. Although both layers are based on noble metals, their surface structures are markedly different. The complexity of such hydrous oxide systems is discussed in detail with the goal of identifying the film composition more precisely.

Starting from subsurface Zr0-doped “inverse” Pd and bulk-intermetallic Pd0Zr0 model catalyst precursors, we investigated the dry reforming reaction of methane (DRM) using synchrotron-based near ambient pressure in-situ X-ray photoelectron spectroscopy (NAP-XPS), in-situ X-ray diffraction and catalytic testing in an ultrahigh-vacuum-compatible recirculating batch reactor cell. Both intermetallic precursors develop a Pd0–ZrO2 phase boundary under realistic DRM conditions, whereby the oxidative segregation of ZrO2 from bulk intermetallic PdxZry leads to a highly active composite layer of carbide-modified Pd0 metal nanoparticles in contact with tetragonal ZrO2. This active state exhibits reaction rates exceeding those of a conventional supported Pd–ZrO2 reference catalyst and its high activity is unambiguously linked to the fast conversion of the highly reactive carbidic/dissolved C-species inside Pd0 toward CO at the Pd/ZrO2 phase boundary, which serves the role of providing efficient CO2 activation sites. In contrast, the near-surface intermetallic precursor decomposes toward ZrO2 islands at the surface of a quasi-infinite Pd0 metal bulk. Strongly delayed Pd carbide accumulation and thus carbon resegregation under reaction conditions leads to a much less active interfacial ZrO2–Pd0 state.