Surface SciencePub Date : 2025-01-13DOI: 10.1016/j.susc.2025.122696
Georg Held
{"title":"Structure determination by low-energy electron diffraction—A roadmap to the future","authors":"Georg Held","doi":"10.1016/j.susc.2025.122696","DOIUrl":"10.1016/j.susc.2025.122696","url":null,"abstract":"<div><div>Of all experimental Surface Science techniques, LEED-IV surface crystallography delivers the most complete set of crystallographic data for the near-surface regions (down to <span><math><mrow><mo>≈</mo><mn>10</mn></mrow></math></span> Å below the surface) of ordered single crystal surfaces. In the last five decades a large number of surface structures have been determined but theoretical and experimental procedures need to be adopted to meet the requirements of new directions in Surface Science. In this perspective article approaches will be discussed for extracting structural information from disordered and rough surfaces, increasing the experimental data set for large unit cells with complex unit cells, improving the scattering potentials used to calculate LEED-IV curves, and expanding the pressure range of the technique.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"754 ","pages":"Article 122696"},"PeriodicalIF":2.1,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Intercalation of Mn in a few layers of NbSe2 by molecular beam epitaxy","authors":"Vimukthi Pathirage, Salma Khatun, Matthias Batzill","doi":"10.1016/j.susc.2025.122695","DOIUrl":"10.1016/j.susc.2025.122695","url":null,"abstract":"<div><div>Modifications of NbSe<sub>2</sub> ultrathin films by intercalation of Mn ions is investigated. The synthesis consists of a two-step approach. First NbSe<sub>2</sub> ultrathin films are grown by van der Waals epitaxy on either graphite (HOPG) or MoS<sub>2</sub> substrates. Optimized growth conditions show that at low growth temperatures of 250 °C phase-pure NbSe<sub>2</sub> is obtained. These films are then modified by a topotactical reaction with small amounts of vapor deposited Mn atoms. It is shown by combination of x-ray photoemission spectroscopy and low energy He-ion scattering spectroscopy that 0.2 to 0.3 monolayer-equivalent amounts of Mn atoms can react with the NbSe<sub>2</sub> and intercalate in between NbSe<sub>2</sub> layers before Mn adsorption occurs at the surface. The intercalation is confirmed by scanning tunneling microscopy (STM). The Mn ions remain disordered in the intercalation layer as evidenced by STM and low energy electron diffraction. Although the Mn<sup>2+</sup> ions are in a high spin state long range magnetic ordering may be frustrated by the structural disorder. Nevertheless, the demonstration of hetero-TM intercalation into TMD layers is an important step in the synthesis of van der Waals crystals modified by elements with large magnetic moments.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"754 ","pages":"Article 122695"},"PeriodicalIF":2.1,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143150347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Surface SciencePub Date : 2025-01-08DOI: 10.1016/j.susc.2025.122694
Elias Diesen , Mehmet Ugur Coskun , Sergio Díaz-Coello , Vanessa J. Bukas , Julia Kunze-Liebhäuser , Karsten Reuter
{"title":"Rationalizing the “anomalous” electrochemical Stark shift of CO at Pt(111) through vibrational spectroscopy and density-functional theory calculations","authors":"Elias Diesen , Mehmet Ugur Coskun , Sergio Díaz-Coello , Vanessa J. Bukas , Julia Kunze-Liebhäuser , Karsten Reuter","doi":"10.1016/j.susc.2025.122694","DOIUrl":"10.1016/j.susc.2025.122694","url":null,"abstract":"<div><div>We employ infrared reflection absorption spectroscopy (IRRAS) and first-principles density-functional theory (DFT) to revisit the reported “anomalous” negative Stark shift of the CO stretch frequency at Pt(111) in aqueous electrolyte. Our comprehensive IRRAS measurements confirm the existence of a potential region with negative Stark shift around 0.5<!--> <!-->V vs. the reversible hydrogen electrode, but only at a sufficiently high CO concentration in the electrolyte. As these are exactly the same conditions for the occurrence of a phase transition from a <span><math><mrow><mo>(</mo><mn>2</mn><mo>×</mo><mn>2</mn><mo>)</mo></mrow></math></span>-3CO to a <span><math><mrow><mo>(</mo><msqrt><mrow><mn>19</mn></mrow></msqrt><mo>×</mo><msqrt><mrow><mn>19</mn></mrow></msqrt><mo>)</mo></mrow></math></span>R23.4<span><math><mo>°</mo></math></span>-13CO adsorbate structure, we explicitly compute the Stark shift for these two phases using DFT. Neither phase exhibits a negative Stark shift, but the absolute stretch frequencies of the atop CO in the two structures are slightly shifted with respect to each other. Remeasuring IRRAS with high resolution indeed reveals a doublet character of the absorption band in the potential region corresponding to the negative Stark shift. Separate fits of the two components then yield positive Stark shifts in quantitative agreement with the calculated values. The “anomalous” negative Stark shift simply arises from effectively fitting one component to a doublet spectral feature in a potential range with phase coexistence at the surface.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"754 ","pages":"Article 122694"},"PeriodicalIF":2.1,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Surface SciencePub Date : 2025-01-01DOI: 10.1016/j.susc.2024.122688
Emanuel Colombi Manzi , Michail Stamatakis , Giovanni Di Liberto , Gianfranco Pacchioni
{"title":"Hydrogen complexes on single-atom alloys: A combined DFT – Kinetic Monte Carlo study","authors":"Emanuel Colombi Manzi , Michail Stamatakis , Giovanni Di Liberto , Gianfranco Pacchioni","doi":"10.1016/j.susc.2024.122688","DOIUrl":"10.1016/j.susc.2024.122688","url":null,"abstract":"<div><div>Single-Atom Catalysts (SACs) are a new class of solid catalysts with potential applications in a wide spectrum of chemical reactions. The family of Single Atom Alloys (SAAs) is promising for hydrogen-related reactions. One interesting aspect of SACs is that their chemistry is reminiscent of coordination chemistry, and a pertinent example is the formation of dihydrogen complexes in hydrogen-related reactions with similarities to coordination compounds. The formation of these hydrogen complexes has been suggested also for SAAs, based on density functional theory (DFT) calculations. In this work, we conducted a study combining DFT with Kinetic Monte Carlo (KMC) to investigate the formation of hydrogen complexes on a set of SAAs. We scrutinized 14 SAAs with DFT and performed KMC simulations on three relevant cases. Our study considers explicitly the kinetic barriers for the formation and decomposition of these complexes to elucidate the kinetics of the adsorption of molecular H<sub>2</sub> on SAAs. The results indicate that the new species can be relevant depending both on their stability and the reaction barriers involved. In particular, we focused on three test cases, Co@Rh(111), Pd@Rh(111) and Co@Au(111) showing that the formation of dihydrogen species, H<sub>2</sub>*, where * indicates an adsorbed complex, can affect the formation of the complex from molecular H<sub>2</sub>.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"754 ","pages":"Article 122688"},"PeriodicalIF":2.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Surface SciencePub Date : 2025-01-01DOI: 10.1016/j.susc.2024.122693
Hanna Sjö , Anatoly Shabalin , Ulrich Lienert , Johan Hektor , Andreas Schaefer , Per-Anders Carlsson , Carl Alwmark , Johan Gustafson
{"title":"Surface grain orientation mapping using grazing incidence X-ray diffraction","authors":"Hanna Sjö , Anatoly Shabalin , Ulrich Lienert , Johan Hektor , Andreas Schaefer , Per-Anders Carlsson , Carl Alwmark , Johan Gustafson","doi":"10.1016/j.susc.2024.122693","DOIUrl":"10.1016/j.susc.2024.122693","url":null,"abstract":"<div><div>Tomographic surface X-ray diffraction (TSXRD) is an adaptation of classic surface X-ray diffraction to allow for measurements of polycrystalline surfaces. Compared to most other surface-sensitive techniques, surface X-ray diffraction has advantages in <em>operando</em> studies, since it can provide crystallographic information about surface structures in high gas pressures (above atmospheric) as well as through liquids. The method has, however, so far been limited to ideal samples, such as single crystals, since the long beam footprint illuminates several grains, which, with conventional SXRD, prevents an assignment of the diffraction signal and thus the structural information, to a certain grain. Here, we present the first step in the development of TSXRD, in which the grain shapes and orientations on a polycrystalline surface can be mapped using grazing incidence X-ray diffraction. The resulting knowledge about the shape, position, and orientation of the grains at the surface will be the steppingstone for further SXRD analysis of polycrystalline surfaces, allowing us to identify which diffraction signals belong to which grain. This method is thus part of opening up SXRD as a method for <em>operando</em> studies of more industry-relevant samples. Our grain maps are compared to those obtained with electron back-scatter diffraction measurements of the same sample, confirming the validity of the method.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"754 ","pages":"Article 122693"},"PeriodicalIF":2.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143150346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Surface SciencePub Date : 2024-12-29DOI: 10.1016/j.susc.2024.122692
Hui-Ling Shui , Gao-Yi Li , Chao Fu , Dong-Heng Li , Xiao-Qin Liang , Kai Li , Laicai Li , Yan Zheng
{"title":"A DFT study on the structural properties and CO2 electrocatalytic reduction activity of monolayer graphitic carbon nitride supported Ag/Au single atom catalysts","authors":"Hui-Ling Shui , Gao-Yi Li , Chao Fu , Dong-Heng Li , Xiao-Qin Liang , Kai Li , Laicai Li , Yan Zheng","doi":"10.1016/j.susc.2024.122692","DOIUrl":"10.1016/j.susc.2024.122692","url":null,"abstract":"<div><div>In this study, the DFT has been utilized to research the structural characteristics and CO<sub>2</sub> reduction performances of g-C<sub>3</sub>N<sub>4</sub> supported Ag and Au single-atom electrocatalysts, namely Ag-C<sub>3</sub>N<sub>4</sub> and Au-C<sub>3</sub>N<sub>4</sub> respectively. The constructed structures have been optimized and both the electron density and charge density difference have been calculated, confirming the stability of the constructed single-atom catalysts (SACs). As demonstrated by charge density difference analysis, the CO<sub>2</sub> undergoes chemical adsorption on Ag-C<sub>3</sub>N<sub>4</sub> and Au-C<sub>3</sub>N<sub>4</sub>, resulting in the activation of CO<sub>2</sub>. Furthermore, the microscopic mechanisms for the formation of HCOOH, CO, CH<sub>3</sub>OH and CH<sub>4</sub> from electrocatalytic CO<sub>2</sub> reduction reaction (CO<sub>2</sub>RR) on these SACs have been fully investigated. Specifically, all structures of the reactants, products, and intermediates have been optimized, and their adsorption energy, zero-point energy, and free energy changes have been calculated. Subsequently, the product selectivity differences between Ag-C<sub>3</sub>N<sub>4</sub> and Au-C<sub>3</sub>N<sub>4</sub> catalysts are compared. Our findings show that Ag-C<sub>3</sub>N<sub>4</sub> catalyzes CO<sub>2</sub> to CH<sub>3</sub>OH and CH<sub>4</sub> with similar efficiency, while Au-C<sub>3</sub>N<sub>4</sub> more effectively facilitates the conversion of CO<sub>2</sub> to CH<sub>3</sub>OH over HCOOH and CH<sub>4</sub>. Furthermore, by analyzing the free energy change values of rate-determining step for generating four types of C1 products, we find that Ag-C<sub>3</sub>N<sub>4</sub> exhibits superior CO<sub>2</sub> catalytic performance over Au-C<sub>3</sub>N<sub>4</sub>. Moreover, the hydrogen evolution reaction (HER) on these catalysts has been investigated, revealing that HER is inhibited on both catalyst surfaces. This finding emphasizes the preferential electrocatalytic reduction of CO<sub>2</sub> on these catalysts. Through calculations of the energy band and density of state of the catalysts, it is found that the energy gap of Ag-C<sub>3</sub>N<sub>4</sub> is smaller than that of Au-C<sub>3</sub>N<sub>4</sub>. This correlation suggests that a smaller energy gap is indicative of stronger catalytic activity, which is further evidenced by the higher activity of Ag-C<sub>3</sub>N<sub>4</sub> in the electrocatalytic reduction of CO<sub>2</sub> compared to Au-C<sub>3</sub>N<sub>4</sub>. Our results reveal that both Ag-C<sub>3</sub>N<sub>4</sub> and Au-C<sub>3</sub>N<sub>4</sub> exhibit strong activity in the electrocatalytic CRR. These results establish a theoretical basis for the development of single-atom catalysts (SACs) that can efficiently reduce CO<sub>2</sub> through electrocatalysis.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"754 ","pages":"Article 122692"},"PeriodicalIF":2.1,"publicationDate":"2024-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143150348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Surface SciencePub Date : 2024-12-27DOI: 10.1016/j.susc.2024.122679
Dajo Boden, Jörg Meyer, Irene M.N. Groot
{"title":"The effect of NO and CO on the Rh(100) surface at room temperature and atmospheric pressure","authors":"Dajo Boden, Jörg Meyer, Irene M.N. Groot","doi":"10.1016/j.susc.2024.122679","DOIUrl":"10.1016/j.susc.2024.122679","url":null,"abstract":"<div><div>Rhodium is used in automotive catalysis to reduce NO and CO emission by catalyzing the reduction of NO to N<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> and the oxidation of CO to CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>. Rhodium nanoparticles in the catalyst are exposed to high pressures of NO and CO, which leads to disintegration and sintering of the catalyst. To design more stable catalysts, the effects of high pressures of NO and CO on rhodium must be understood. Therefore, we studied the Rh(100) surface, which is most active for NO reduction by CO, at atmospheric pressures of NO and CO with scanning tunneling microscopy. Atomistic thermodynamics, low-energy electron diffraction, and Auger electron spectroscopy were used to understand the behavior of adsorbates on the surface. We observe the formation of rhodium islands and roughening of the step edges at high CO pressures. Roughening does not occur at the same pressures of NO, and is also less severe when co-dosing NO and CO, even at identical CO partial pressures. Atomistic thermodynamics shows that NO likely inhibits CO adsorption by blocking adsorption sites, preventing carbonyl formation, and decreasing surface roughening.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"754 ","pages":"Article 122679"},"PeriodicalIF":2.1,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Surface SciencePub Date : 2024-12-27DOI: 10.1016/j.susc.2024.122691
Hyunwoo Jang, Seungwon Shim, Youngho Kang
{"title":"Impact of Ni doping on the catalytic activity and stability of RuO2 electrocatalyst for the oxygen evolution reaction in acidic media","authors":"Hyunwoo Jang, Seungwon Shim, Youngho Kang","doi":"10.1016/j.susc.2024.122691","DOIUrl":"10.1016/j.susc.2024.122691","url":null,"abstract":"<div><div>Doping with transition metals (TMs) has been recognized as an effective strategy to improve the material stability of RuO<sub>2</sub> electrocatalysts for the oxygen evolution reaction (OER). However, the detailed mechanisms of material degradation and the impact of TM doping remain unclear. In this work, using density functional theory (DFT) calculations, we demonstrate that the experimental conditions under which OER proceeds can also trigger the degradation of RuO<sub>2</sub> through Ru dissolution, and that Ni doping can suppress this dissolution process. Specifically, the formation of RuO<sub>4</sub>(<em>aq</em>), a product of the dissolution reaction, becomes thermodynamically favorable at a bias comparable to OER overpotentials. Ni doping makes RuO<sub>4</sub> formation less favorable without significantly altering the OER pathway. Furthermore, the Ru-O bond near a Ni dopant becomes stronger, making the reaction pathway for Ru dissolution more difficult to proceed. By expanding the atomistic understanding of the role of Ni doping on OER and material stability, this work paves the way for the development of high-performance and sustainable electrocatalysts for water splitting.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"754 ","pages":"Article 122691"},"PeriodicalIF":2.1,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143150350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Surface SciencePub Date : 2024-12-26DOI: 10.1016/j.susc.2024.122685
Ke Ri Liang , Rich P. Mildren , Catherine Stampfl
{"title":"Diamond surface nano-structures in an oxidizing atmosphere: A first principles study","authors":"Ke Ri Liang , Rich P. Mildren , Catherine Stampfl","doi":"10.1016/j.susc.2024.122685","DOIUrl":"10.1016/j.susc.2024.122685","url":null,"abstract":"<div><div>Diamond’s unique properties has found it numerous applications in electronics, optics and medicine. As desirable are diamond’s potential applications, it is notoriously difficult to process on the nanoscale. A new and promising mechanism involving a two-photon laser induced desorption could solve many of these problems. However, the underlying mechanism of this process is still not well understood; what is known, is that oxygen plays an important role. Therefore a detailed and consistent understanding of the fundamental behaviour of oxygen on diamond surfaces is required. In the present paper, systematic density-functional theory calculations are performed to investigate the interaction of oxygen with the low-index surfaces of diamond, taking into account the effect of pressure and temperature. This affords predictions of the surface atomic structures, including the newly discovered keto-ether structure on the <span><math><mrow><mi>C</mi><mrow><mo>(</mo><mn>110</mn><mo>)</mo></mrow></mrow></math></span> surface, and the associated properties such as the adsorption energies, work-function, surface dipole moment, electron density difference, density of states, and electronic bandstructure. By including the effect of the environment, namely, the oxygen pressure and temperature in which the surface is held, surface phase diagrams are obtained. From these results, and using the Wulff construction, the shape of oxygen-terminated nanoparticles are predicted. Further, using the calculated surface free energies, the surface populations of different structures on the <span><math><mrow><mi>C</mi><mrow><mo>(</mo><mn>100</mn><mo>)</mo></mrow></mrow></math></span>, <span><math><mrow><mi>C</mi><mrow><mo>(</mo><mn>110</mn><mo>)</mo></mrow></mrow></math></span> and <span><math><mrow><mi>C</mi><mrow><mo>(</mo><mn>111</mn><mo>)</mo></mrow></mrow></math></span> surfaces as a function of temperature, for both atmospheric pressure and ultra high vacuum conditions are evaluated. Interestingly, the results predict that although the full monolayer bridge site on <span><math><mrow><mi>C</mi><mrow><mo>(</mo><mn>100</mn><mo>)</mo></mrow></mrow></math></span> has the highest population, the top site ketone structure can be populated by as much as 20% and coexist. Regarding the half monolayer bridge structure on the reconstructed <span><math><mrow><mi>C</mi><mrow><mo>(</mo><mn>111</mn><mo>)</mo></mrow><mo>−</mo><mrow><mo>(</mo><mn>1</mn><mo>×</mo><mn>2</mn><mo>)</mo></mrow></mrow></math></span> surface, the bandstructure shows that it possesses no surface states in the band gap making it attractive for quantum sensing applications and is the most favourable structure at this coverage. Interestingly, the calculations predict another structure that is only 0.02 eV less favourable and so is likely to coexist on the surface. Overall, the present work provides a most comprehensive theoretical understanding of the interaction of oxygen with the low index diamond surfaces,","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"754 ","pages":"Article 122685"},"PeriodicalIF":2.1,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143150349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}