ACS Catalysis 最新文献

{"title":"Strengthened Delocalized Electronic Effect in Nano-Nickel@Carbon with High Pyrrolic Nitrogen for Selective Hydrogenation of Substituted Nitrobenzene Hydrogenation","authors":"Yongyue Yao, Chunyu Yin, Wei He, Yebin Zhou, Chaofan Ma, Yi Liu, Xiaonian Li, Chunshan Lu","doi":"10.1021/acscatal.4c03995","DOIUrl":"https://doi.org/10.1021/acscatal.4c03995","url":null,"abstract":"Carbon-encapsulated metal (CEM) catalysts reconfigure the active site of the catalytic reaction by shifting from the conventional metal to the surface of the carbon material. Carbon-encapsulated structure has attracted wide attention in the fields of electrochemistry, thermal catalysis and photocatalysis. Herein, a nitrogen-doped carbon-encapsulated nickel catalyst was synthesized via hydrothermal synthesis, with pyrrolic N (N_Pyr) content accounting for 48.4% of the total nitrogen species. Experiments and density functional theory calculations reveal that the five-membered pyrrole ring shares six π electrons, and its electron cloud density on the carbon surface surpasses that of benzene or pyridine ring, promoting extensive electronic interaction between N_PyrC and nickel. The interaction also extends beyond the vicinity of the doping sites and permeates throughout the entire carbon shell, thereby augmenting a greater number of potential active sites on the NC layer. This strengthened delocalized electronic effect imparts specificity in the adsorption and dissociation processes of hydrogen and <i>p</i>-chloronitrobenzene, leading to enhanced catalytic performance in the hydrogenation production of <i>p</i>-chloroaniline. The precise preparation of N_Pyr-doped CEM catalysts demonstrates its huge potential for industrial applications.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142317401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reactive Surface Explored by NAP-XPS: Why Ionic Conductors Are Promoters for Water Gas Shift Reaction","authors":"Nuria García-Moncada, Anna Penkova, Miriam González-Castaño, José A. Odriozola","doi":"10.1021/acscatal.4c04287","DOIUrl":"https://doi.org/10.1021/acscatal.4c04287","url":null,"abstract":"Near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) experiments have been carried out in N₂ and N₂–H₂O atmospheres on a Pt-based catalyst physically mixed with an Eu-doped ZrO₂ ionic conductor as a function of temperature under realistic conditions of the water gas shift (WGS) reaction. This work aims to demonstrate the significant effect of having active H₂O on the ionic conductor surface at reaction temperatures to provide it to Pt metal sites. The ionic conductor, Eu-doped zirconia matrix, presents defects (oxygen vacancies, O_v) that allows upon H₂O dissociation the formation of a hydrogen-bonded molecular water layer favoring diffusion through a Grotthuss mechanism below 300 °C. In the presence of H₂O, the O_v are occupied by hydroxyl species as observed in the Eu 4d spectra, which differentiate two types of Eu oxidation states. The Eu³⁺-to-Eu²⁺ atomic ratio increases with the occupancy of the O_v by hydroxyls. Moreover, while the Pt-based catalyst alone is unable to create Pt–OH bonds, the physical mixture of the Pt-based catalyst and the ionic conductor allows the formation of Pt–OH bonds from room temperature up to 300 °C. These data demonstrate that the increase in molecular water concentration on the ionic conductor surface up to 300 °C acts as a reservoir to provide water to the Pt surface, enhancing the catalyst performance in the WGS reaction, supporting the importance of the surface H₂O concentration in the reaction kinetics.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142321069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Perovskite Oxide Materials for Solar Thermochemical Hydrogen Production from Water Splitting through Chemical Looping","authors":"Cijie Liu, Jiyun Park, Héctor A. De Santiago, Boyuan Xu, Wei Li, Dawei Zhang, Lingfeng Zhou, Yue Qi, Jian Luo, Xingbo Liu","doi":"10.1021/acscatal.4c03357","DOIUrl":"https://doi.org/10.1021/acscatal.4c03357","url":null,"abstract":"Solar-driven thermochemical hydrogen (STCH) production represents a sustainable approach for converting solar energy into hydrogen (H₂) as a clean fuel. This technology serves as a crucial feedstock for synthetic fuel production, aligning with the principles of sustainable energy. The efficiency of the conversion process relies on the meticulous tuning of the properties of active materials, mostly commonly perovskite and fluorite oxides. This Review conducts a comprehensive review encompassing experimental, computational, and thermodynamic and kinetic property studies, primarily assessing the utilization of perovskite oxides in two-step thermochemical reactions and identifying essential attributes for future research endeavors. Furthermore, this Review delves into the application of machine learning (ML) and density functional theory (DFT) for predicting and classifying the thermochemical properties of perovskite materials. Through the integration of experimental investigations, computational modeling, and ML methodologies, this Review aspires to expedite the screening and optimization of perovskite oxides, thus enhancing the efficiency of STCH processes. The overarching objective is to propel the advancement and practical integration of STCH systems, contributing significantly to the realization of a sustainable and carbon-neutral energy landscape.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142321068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pt-Loaded CoFe-Layered Double Hydroxides for Simultaneously Driving HER and HzOR","authors":"Tianrui Yu, Guihao Liu, Tianqi Nie, Zhaohui Wu, Ziheng Song, Xiaoliang Sun, Yu-Fei Song","doi":"10.1021/acscatal.4c03881","DOIUrl":"https://doi.org/10.1021/acscatal.4c03881","url":null,"abstract":"Hydrazine-assisted water electrolysis presents an energy-saving pathway for H₂ production. However, due to the different electronic structure requirements for active metals in hydrogen evolution reaction (HER) and hydrazine oxidation reaction (HzOR) reactions, catalysts capable of simultaneously driving HER and HzOR are less studied. Herein, we employ an electrochemical deposition method to load 4.2 nm Pt nanoparticles onto CoFe-layered double hydroxides. The resultant Pt/CoFe/NF requires only 12.1 and 28.7 mV to achieve 50 and 100 mA cm^–2 for HzOR and an ultralow overpotential of 16.5 mV with a Tafel slope of 31.4 mV dec^–1 to achieve 10 mA cm^–2 for HER. The Pt/CoFe/NF-based overall hydrazine splitting (OHzS) device can realize 10 and 100 mA cm^–2 at low potential of 0.093 and 0.531 mV, respectively, and the Faradaic efficiency for both N₂ and H₂ generation reaches nearly 100%. Such HER and HzOR activities can be attributed to the electronic metal–support interaction (EMSI) between Pt and CoFe/NF, which modulates the d-band center of Pt to an optimal position, thereby balancing the adsorption of N₂H₄ molecules (Δ<i>G</i>_*N₂H₄ = −2.27 eV) and the desorption of hydrogen (Δ<i>G</i>_H* = −0.18 eV) by Pt/CoFe/NF. This work provides insights into the design of efficient bifunctional catalysts from the perspective of the electronic structure.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142325056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nature of Glucose Epimerization Catalyzed by Mo-Containing Bulk Catalysts in Aqueous Phase","authors":"Miao Liu, Ying He, Ying-Ying Jiao, Ling Ding, Di An, Yang Yang, Qing-Qing Hao, Hui-Yong Chen, Qun-Xing Luo","doi":"10.1021/acscatal.4c02893","DOIUrl":"https://doi.org/10.1021/acscatal.4c02893","url":null,"abstract":"The nature of Mo-catalyzed glucose epimerization in the aqueous phase was elaborately studied. We herein formulate the thermodynamic properties (<i>e.g</i>., Δ_r<i>H_T</i>, Δ_r<i>G_T</i>, and <i>K</i>_eq<i>.T</i>) of the reversible epimerization by collecting the equilibrium composition. The isotopic tracing and NMR spectra show that the overall tautomerization network encompasses the reversible epimerization and isomerization and the irreversible degradation of all hexoses. The leaching tests and kinetic and spectroscopic studies reveal that glucose epimerization catalyzed by Mo-containing solid catalysts in the aqueous phase resembles homogeneous catalysis. All catalysts enable a near-equilibrium yield of mannose (28%) at 373 K except MoP but undergo a different kinetic course of which MoN is the best catalyst according to the apparent kinetic parameters. The molybdenum species dissolved in an aqueous solution evolves into the truly active centers of the Mo^VI–O–Mo^VI bridged polymolybdates. Moreover, we propose that a single Mo center as Lewis acidic site coordinates with the aldoses to form a bidentate complex, which thereby contributes two different mechanisms to generate the epimers, viz., the intramolecular 1, 2-carbon exchange and two-step isomerization. The former proceeds through a three-membered cyclic transition state (TS_C) that mediates the simultaneous cleavage of the bond between C-2 and C-3 and formation of the bond between C-1 and C-3, whereas the latter undergoes two hydride transition states (TS_H-1 and TS_H-2) via the hydride transfer twice, leading to the chiral inversion of the configuration at C-2. Last but not least, the presence of phosphates in an aqueous solution leads to the deactivation of Mo-based catalysts because of the interplay between glucose and phosphates.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142317228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In Situ Facet Transformation Engineering over Co3O4 for Highly Efficient Electroreduction of Nitrate to Ammonia","authors":"Suwei Lu, Guanting Lin, Hongping Yan, Yuhang Li, Tingting Qi, Yuanjin Li, Shijing Liang, Lilong Jiang","doi":"10.1021/acscatal.4c05292","DOIUrl":"https://doi.org/10.1021/acscatal.4c05292","url":null,"abstract":"Various exposed facets can cause a huge difference in the catalytic activity. Here we prepared Co₃O₄ hexagonal nanosheets with exposed {112}, {112}&amp;{111}, and {111} facets for the electrochemical nitrate reduction reactions (NO₃RR). The reaction pathways of the NO₃RR on Co₃O₄ {111} and {112} facets are clarified through in situ electrochemical characterizations and theoretical analysis. As the dominating facet of Co₃O₄ transforms from {112} to {111}, the rate-determining step changes from *NO₂ → *NO₂H to *NO₃H → *NO₂, with the energy barrier decreasing to 0.48 eV. And the {111} facet promotes the hydrogenation of NO_<i>x</i> and NH_<i>x</i> intermediates. Notably, the Co₃O₄-{111} catalyst shows exceptional NO₃RR performance, achieving an NH₃ yield of 5.73 mg mg_cat.^–1 h^–1, surpassing the majority of the reported activities.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142313639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enantioselective Synthesis of Chiral 1,4-Enynes via Palladium-Catalyzed Branch-Selective Allylic C–H Alkylation","authors":"Yazhou Lou, Zihan Lin, Chenxi Wu, Zhong-Sheng Nong, Rui Liu, Liu-Zhu Gong","doi":"10.1021/acscatal.4c04642","DOIUrl":"https://doi.org/10.1021/acscatal.4c04642","url":null,"abstract":"We herein present the construction of a chiral 1,4-enyne featuring tertiary or quaternary stereogenic center via Pd-catalyzed branch-, enantio-, and diastereoselective allylic C–H alkylation. Alkynyl carbon bearing bulky substituents appeared to exhibit competitive reaction performance, and the desired chiral 1,4-enynes were obtained in up to 93% yield and with up to &gt;20:1 b/l, &gt;20:1 dr, and 98% ee. A gram-scale experiment, the feasible operation of benzothiazole ring, and the preparation of the key intermediate to access (+)-Breynolide and prostaglandin are represented as a demonstration of multifarious synthetic utility in chemical synthesis.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142317230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Precision Structure Engineering of High-Entropy Oxides under Ambient Conditions","authors":"Kevin M. Siniard, Meijia Li, Yandi Cai, Junyan Zhang, Felipe Polo-Garzon, Darren M. Driscoll, Alexander S. Ivanov, Xinhui Lu, Hao Chen, Yuanyuan Li, Zili Wu, Zhenzhen Yang, Sheng Dai","doi":"10.1021/acscatal.4c03349","DOIUrl":"https://doi.org/10.1021/acscatal.4c03349","url":null,"abstract":"High-entropy oxides (HEOs) have unveiled a unique frontier in the realm of heterogeneous catalysis, taking advantage of the entropic effect and increased complexities to deliver ultrahigh stability and large tuning capability. However, current HEO synthesis mainly relies on high-temperature annealing approaches affording HEOs possessing no or low surface area, inferior active site exposure efficiency, and low controllability over the structure tuning. The grand challenge lies in producing high-quality HEO catalysts with high active site utilization efficiency, which relies on precision structure engineering, preferably under mild conditions. In this work, an in situ lattice engineering approach was developed to afford a supported HEO catalyst under ambient conditions. The HEO compositions (CuCoFeNiMnO_<i>x</i>) were uniformly integrated into the lattice of CeO₂ driven by cavitation-induced nucleation being generated via ultrasonication. The as-afforded catalysts were featured by high surface area, atomically dispersed HEO compositions, active redox properties, abundant oxygen vacancies (O_V), antiagglomeration, and high phase stability under harsh conditions. Compared with the ex situ introduction of HEO on the surface, the in situ method provides dual benefits to maintain the dispersity of HEO via entropic and lattice confinement effects. Engineering the complex HEO within the lattice of fluorite-structured CeO₂ also yields abundant defects (e.g., O_V) and active metal sites with strong reducing properties (e.g., Ce³⁺ and Cu⁺), which greatly improves the activity of the lattice oxygen and tunability of the adsorption behavior of the guest molecules, especially in the presence of impurities (e.g., water and propane). The catalytic performance of the supported HEO catalyst in oxidative procedures surpasses the pure dense phase HEO as well as the ex situ-generated catalysts. The synthesis approach being developed in this work, together with the fundamental understanding in structure evolution and reaction mechanism, showcases a facile pathway under ambient conditions to generate stable catalysts capable of maintaining structural robustness in high-temperature conditions while delivering enhanced catalytic performance.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142276778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lifecycle of Pd Clusters: Following the Formation and Evolution of Active Pd Clusters on Ceria During CO Oxidation by In Situ/Operando Characterization Techniques","authors":"Daria Gashnikova, Florian Maurer, Miriam R. Bauer, Sarah Bernart, Jelena Jelic, Mads Lützen, Carina B. Maliakkal, Paolo Dolcet, Felix Studt, Christian Kübel, Christian D. Damsgaard, Maria Casapu, Jan-Dierk Grunwaldt","doi":"10.1021/acscatal.4c02077","DOIUrl":"https://doi.org/10.1021/acscatal.4c02077","url":null,"abstract":"For maximizing the atomic efficiency in noble metal-based catalysts, dedicated preparation routes and high lifetime are essential. Both aspects require an in-depth understanding of the fate of noble metal atoms under reaction conditions. For this purpose, we used a combination of complementary <i>in situ/operando</i> characterization techniques to follow the lifecycle of the Pd sites in a 0.5% Pd/5% CeO₂–Al₂O₃ catalyst during oxygen-rich CO oxidation. Time-resolved X-ray absorption spectroscopy showed that Pd cluster formation under reaction conditions is important for a high CO oxidation activity. In combination with density functional theory calculations, we concluded that the ideal Pd cluster size amounts to about 10–30 Pd atoms. The cluster formation and stability were affected by the applied temperature and reaction conditions. Already short pulses of 1000 ppm CO in the lean reaction feed were found to trigger sintering of Pd at temperatures below 200 °C, while at higher temperatures oxidation processes prevailed. Environmental transmission electron microscopy unraveled redispersion at higher temperatures (400–500 °C) in oxygen atmosphere, leading to the formation of single sites and thus the loss of activity. However, due to the reductive nature of CO, clusters formed again upon cooling in reaction atmosphere, thus closing the catalytic cycle. Exploiting the gained knowledge on the lifecycle of Pd clusters, we systematically investigated the effect of catalyst composition on the cluster formation tendency. As uncovered by DRIFTS measurements, the Pd to CeO₂ ratio seems to be a key descriptor for Pd agglomeration under reaction conditions. While for higher Pd loadings, the probability of cluster formation increased, a higher CeO₂ content leads to the formation of oxidized dispersed Pd species. According to our results, a Pd:CeO₂ weight ratio of 1:10 for CeO₂–Al₂O₃-supported catalysts leads to the highest CO oxidation activity under lean conditions independent of the applied synthesis method.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142313640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simultaneous Photocatalytic Production of H2 and Acetal from Ethanol with Quantum Efficiency over 73% by Protonated Poly(heptazine imide) under Visible Light","authors":"Vitaliy Shvalagin, Nadezda Tarakina, Bolortuya Badamdorj, Inga-Marie Lahrsen, Eleonora Bargiacchi, Andre Bardow, Ziqi Deng, Wenchao Wang, David Lee Phillips, Zhengxiao Guo, Guigang Zhang, Junwang Tang, Oleksandr Savateev","doi":"10.1021/acscatal.4c04180","DOIUrl":"https://doi.org/10.1021/acscatal.4c04180","url":null,"abstract":"In this work, protonated poly(heptazine imide) (H-PHI) was obtained by adding acid to the suspension of potassium PHI (K-PHI) in ethanol. It was established that the obtained H-PHI demonstrates very high photocatalytic activity in the reaction of hydrogen formation from ethanol in the presence of Pt nanoparticles under visible light irradiation in comparison with K-PHI. This enhancement can be attributed to improved efficiency of photogenerated charge transfer to the photocatalyst’s surface, where redox processes occur. Various factors influencing the system’s activity were evaluated. Notably, it was discovered that the conditions of acid introduction into the system can significantly affect the size of Pt (cocatalyst metal) deposition on the H-PHI surface, thereby enhancing the photocatalytic system’s stability in producing molecular hydrogen. It was established that the system can operate efficiently in the presence of air without additional components on the photocatalyst surface to block air access. Under optimal conditions, the apparent quantum yield of molecular hydrogen production at 410 nm is around 73%, the highest reported value for carbon nitride materials to date. The addition of acid not only increases the activity of the reduction part of the system but also leads to the formation of a value-added product from ethanol–1,1-diethoxyethane (acetal) with high selectivity.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142313673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}