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Effect of Mn Promoter on Structure and Performance of K-Co-Mo Catalyst for Synthesis of Higher Alcohols from CO Hydrogenation

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Chinese Journal of Chemical Physics 2016年第6期29卷 671-680,I0001页

作者： Wei Xie Li-li Ji Ji-long Zhou Hai-bin Pan jun-fa zhu Yi Zhang Song Sun jun Bao Chen Gao NationalSynchrotronRadiationLaboratory CollaborativeInnovationCenterofChemistryforEnergyMaterialsUniversityofScienceandTechnologyofChinaHefei230029China StateKeyLaboratoryofOrganic-InorganicComposites BellingUniversityofChemicalTechnologyBeijing100029China CASKeyLaboratoryofMaterialsforEnergyConversion DepartmentofMaterialsScienceandEngineeringUniversityofScienceandTechnologyofChinaHefei230025China

A series of Mn-doped K-Co-Mo catalysts were prepared by a sol-gel method. The catalyst structure was well characterized by X-ray diffraction, N2 physisorption, NH3 temperature- programmed adsorption, in situ diffuse reflectance infrared Fourier transform spectroscopy, and X-ray absorption fine structure spectroscopy. The catalytic performance for higher alcohol synthesis from syngas was measured. It was found that the Mn-doped catalysts ex- hibited a much higher activity as compared to the unpromoted catalyst, and in particular the C2＋ alcohol selectivity increased significantly. The distribution of alcohol products de- viated from the Anderson-Schulz-Flory law. The portion of methanol in total alcohol was suppressed remarkably and the ethanol became the predominant product. Characterization results indicated that the incorporation of Mn enhanced the interaction of Co and Mo and thus led to the formation of Co-Mo-O species, which was regarded as the active site for the alcohol synthesis. Secondly, the presence of Mn reduced the amount of strong acid sites significantly and meanwhile promoted the formation of weak acid sites, which had a positive effect on the synthesis of alcohol. Furthermore, it was found that the incorporation of Mn can enhance the adsorption of linear- and bridge-type CO significantly, which contributed to the formation of alcohol and growth of carbon chain and thus increased the selectivity to C2＋OH.

关键词： CO hydrogenation Sol-gel method Mo-based catalyst Mn promoter Higheralcohols synthesis

Regulated reaction pathway of CO_(2)photoreduction into CH_(4)by metal atom pair sites

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Rare Metals 2024年第9期43卷 4620-4627页

作者： Dong-Po He Guang-Bing Huang jun Hu Yang Wu Xiao-Dong Li Qing-Xia Chen Shan zhu Wen-Sheng Yan jun-fa zhu Yang Pan Xing-Chen Jiao Key Laboratory of Synthetic and Biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringJiangnan UniversityWuxi 214122China Hefei National Research Center for Physical Sciences at Microscale National Synchrotron Radiation LaboratoryUniversity of Science and Technology of ChinaHefei 230026China Max Planck Institute of Microstructure Physics Weinberg 206120 HalleGermany State Grid Anhui Electric Power Research Institute Hefei 230601China

The carbon dioxide(CO_(2))reduction process involves complex protonation,making the resulting product often *** achieve the desired product,it is crucial to manipulate the reaction ***,we build the metal atom pair sites for selective CO_(2)photoreduction into *** a prototype,Ni atom pair sites loaded on the Mo S_(2)nanosheets were synthesized and verified by highresolution transmission electron microscopy(HRTEM),X-ray photoelectron spectroscopy(XPS)and X-rayabsorption near edge structure spectra(XANES).In-situ Fourier transform infrared spectroscopy(FTIR)monitors the*CHO group,a crucial intermediate in CH_(4)production,during CO_(2)photoreduction on the Ni-Mo S_(2)nanosheets,whereas this monitoring is not observed for the Mo S_(2)***,theoretical calculations disclose that over the Ni-Mo S_(2)nanosheet slab,the formation energy of*CHO intermediates is determined to be lower(0.585 e V)than the desorption energy of*CO intermediates for CO production(0.64 e V),implying the higher selectivity of CH_(4)production.

关键词： steps dioxide desired

Interaction of cobalt with ceria thin films and its influence on supported Au nanoparticles

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Chinese Chemical Letters 2017年第8期28卷 1760-1766页

作者： Wei-Jia Wang Yan Wang Qian Xu Huan-Xin Ju Tao Wang Zhi-Jie Tao Shan-Wei Hu jun-fa zhu National Synchrotron Radiation Laboratory and Collaborative Innovation Center of Suzhou Nano Science and Technology University of Science and Technology of ChinaHefei 230029China

The interaction of Co with ceria thin films and its influence on the sintering behavior of Au were investigated by scanning tunneling microscopy（STM）, synchrotron radiation photoemission spectroscopy（SRPES） and X-ray photoelectron spectroscopy（XPS）. The strong interaction between Co and CeO_2（111） leads to oxidation of Co to Co^（2＋） at 300 K, accompanied by partial reduction of ceria surface at low Co coverages. Subsequent Co deposition results in an increasing fraction of metallic Co. Annealing to high temperatures induces Co^（2＋）ions diffuse into the CeO_2 film, while the small metallic Co islands agglomerate into larger ones. The bimetallic Co–Au particles were prepared by deposition of Au on the existing Co particles on ceria surfaces. The sintering behavior of Co–Au bimetallic surfaces is found to be highly determined by the stoichiometry of ceria supports. The addition of Co to the Au/CeO_2 surface suppresses the sintering of Au particles at high temperatures in comparison with that of pure Au particles. However, Au particles are less stable on the Co/CeO_（1.82） layer than on CeO_（1.82） surface.

关键词： Cobalt Gold Ceria SRPES XPS STM

Stability and protection of nanowire devices in air

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Nano Research 2018年第6期11卷 3353-3361页

作者： Zhen He Muhammad Hassan Huan-Xin Ju Rui Wang Jin-Long Wang Jia-Fu Chen jun-fa zhu Jian-Wei Liu Shu-Hong Yu Division of Nanomaterials & Chemistry Hefei National Laboratory for Physical Sciences at the Microscale Collaborative Innovation Center of Suzhou Nano Science and Technology Department of Chemistry CAS Center for Excellence in Nanoscience Hefei Science Center of CAS University of Science and Technology of China Hefei 230026 China National Synchrotron Radiation Laboratory University of Science and Technology of China Hefei230026 China

Nanowire devices have attracted considerable attention because of their unique structure and novel properties, and have opened up significant development opportunities. However, not many studies have focused on their stability and durability under practical conditions, which limits the rapid development of real applications. Herein, we systematically investigate three different treatments, polymer coating, inert atmosphere protection, and thickness-induced self-protection, to protect the tellurium nanowire devices from oxidation when exposed to open air. The degree of oxidation was monitored by examining changes in the valence states of tellurium element and in the morphology of the nanowires~ After the protective treatments, the tellurium nanowire devices showed improved stability and remained stable even after 800 days of storage. This work highlights the importance of investigating the stability of nanowire devices, especially for their practical applications.

关键词： stability protection tellurium nanowires nanowire devices assembly

Natural Nanofibrous Cellulose-Derived Solid Acid Catalysts

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Research 2019年第1期2019卷 1043-1053页

作者： Zhen-Yu Wu Peng Yin Huan-Xin Ju Zhi-Qin Chen Chao Li Si-Cheng Li Hai-Wei Liang jun-fa zhu Shu-Hong Yu Division of Nanomaterials&Chemistry Hefei National Laboratory for Physical Sciences at the MicroscalCAS Center for Excellence in NanoscienceHefei Science Center of CASCollaborative Innovation Center of Suzhou Nano Science and TechnologyDepartment of ChemistryUniversity of Science and Technology of ChinaHefei 230026China National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230026China

Solid acid catalysts(SACs)have attracted continuous research interest in past years as they play a pivotal role in establishing environmentally friendly and sustainable catalytic processes for various chemical *** of low-cost and efcient SACs applicable to diferent catalysis processes are of immense signifcance but still very challenging so ***,we report a new kind of SACs consisting of sulfonated carbon nanofbers that are prepared via incomplete carbonization of low-cost natural nanofbrous cellulose followed by sulphonation with sulfuric *** prepared SACs feature nanofbrous network structures,high specifc surface area,and abundant sulfonate as well as hydroxyl and carboxyl ***,the nanofbrous SACs exhibit superior performance to the state-of-the-art SACs for a wide range of acid-catalyzed reactions,including dimerization of�-methylstyrene,esterifcation of oleic acid,and pinacol *** present approach holds great promise for developing new families of economic but efcient SACs based on natural precursors via scalable and sustainable protocols in the future.

关键词： holds incomplete establishing

Synthesis of PdS_(x)- Mediated Polydymite Heteronanorods and Their Long-Range Activation for Enhanced Water Electroreduction

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Research 2019年第1期2019卷 686-696页

作者： Qiang Gao Rui Wu Yang Liu Ya-Rong Zheng Yi Li Li-Mei Shang Yi-Ming Ju Chao Gu Xu-Sheng Zheng Jian-Wei Liu jun-fa zhu Min-Rui Gao Shu-Hong Yu Division of Nanomaterials&Chemistry Hefei National Laboratory for Physical Sciences at the MicroscaleCAS Center for Excellence in NanoscienceHefei Science Center of CASCollaborative Innovation Center of Suzhou Nano Science and TechnologyDepartment of ChemistryUniversity of Science and Technology of ChinaHefei 230026China National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230026China Dalian National Laboratory for Clean Energy Dalian 116023China

Material interfaces permit electron transfer that modulates the electronic structure and surface properties of catalysts,leading to radically enhanced rates for many important *** conventional thoughts,the nanoscale interfacial interactions have been recently envisioned to be able to afect the reactivity of catalysts far from the ***,demonstration of such unlocalized alterations in existing interfacial materials is rare,impeding the development of new *** report the observation of unprecedented long-range activation of polydymite Ni_(3)S_(4) nanorods through the interfacial interaction created by PdS_(x) nanodots(dot-on-rod structure)for high-performance water catalytic *** results show that this local interaction can activate Ni3S4 rods with length even up to 25 nanometers due to the tailored surface electronic *** anticipate that the long-range efect described here may be also applicable to other interfacial material systems,which will aid the development of newly advanced catalysts for modern energy devices.

关键词： structure interfacial interaction

Adsorption and Reaction of CO on Mo(100)-c(2×2)-N Surface Studied by HREELS

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Chinese Chemical Letters 2000年第3期11卷 275-278页

作者： jun fa zhu.,ian Chang GUO, Run Sheng ZHAI, Xin He BAO, Shu Xian zhuANG ( National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 Department of Chemical Physics. University of Science and Technology of China Natl. Synchrt. Radiation Laboratory Univ. of Sci. and Technol. of China Hefei 230029 China Department of Chemical Physics Univ. of Sci. and Technol. of China Hefei 230026 China State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China

High resolution electron energy loss spectroscopy (HREELS) has been used to investigate the adsorption and reaction of CO on the Mo(100)-c(2×2)N surface. CO directly adsorbed on the N atoms from the c(2×2) layer to form isocyanate (NCO) surface species was found in addition to CO adsorbed on the molybdenum atoms at 120 K. indicating that both Mo and N atoms of the Mo(100)-c(2×2)-N surface are of high reactivities for CO adsorption.

关键词： HREELS adsorption reaction Mo(100)-c(2×2)-N CO.

HREELS Studies on Adsorption and Decomposition of ^(15)NO on Mo(100)-c(2×2)N Surface

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Chinese Chemical Letters 1998年第7期9卷 667-670页

作者： jun fa zhu Shu Xian zhuANG Jian Chang GUO Run Sheng ZHAI Yu Ming CAO Xin He BAO(Department of Chemical Physics, University of Science and Technology of China, Hefei 230026)(State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chine Univ Sci & Technol China Dept Phys Chem Hefei 230026 Peoples R China Chinese Acad Sci Dalian Inst Chem Phys State Key Lab Catalysis Dalian 116023 Peoples R China

High resolution electron energy loss spectroscopy (HREELS) has been used to investigate the adsorPtion and decomposition of 15NO on the Mo(100)-c(2×2)14N surface. At 140K, the 15NO molecu1e could adsorb associatively on atop sites of the Mo and l4N atoms in the nitride layers. On the other hand, a small amount of dissociatCd 15NO also exists. The dissociation of surface nitric oxides species at elevated temperatures caused the oxidation of the surface Mo.

关键词： HREELS adsorption decomposition Mo(100)-c(2 symb2)N, nitric oxides

In situ Investigations of Interfacial Degradation and Ion Migration at CH3NH3PbI3 Perovskite/Ag Interfaces

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Chinese Journal of Chemical Physics 2019年第3期32卷 299-305,I0001,I0013-I0015页

作者： Xiong Li Hong-he Ding Gui-hang Li Yan Wang Zhi-min fang Shang-feng Yang Huan-xin Ju jun-fa zhu National Synchrotron Radiation Laboratory and Department of Chemical Physics University of Science and Technology of ChinaHefei 230029China Hefei National Laboratory for Physical Sciences at the Microscale Key Laboratory of Materials for Energy ConversionChinese Academy of SciencesDepartment of Materials Science and EngineeringSynergetic Innovation Center of Quantum Information & Quantum PhysicsUniversity of Science and Technology of ChinaHefei 230026China

Interfacial properties between perovskite layers and metal electrodes play a crucial role in the device performance and the long-term stability of perovskite solar ***,we report a comprehensive study of the interfacial degradation and ion migration at the interface between CH3NH3PbI3 perovskite layer and Ag *** in situ photoemission spectroscopy measurements,we found that the Ag electrode could induce the degradation of perovskite layers,leading to the formation of PbI2 and AgI species and the reduction of Pb^2+ions to metallic Pb species at the *** unconventional enhancement of the intensities of I 3d spectra provides direct experimental evidences for the migration of iodide ions from CH3NH3PbI3 subsurface to Ag ***,the contact of Ag electrode and perovskite layers induces an interfacial dipole of 0.3 eV at CH3NH3PbI3/Ag interfaces,which may further facilitate iodide ion diffusion,resulting in the decomposition of perovskite layers and the corrosion of Ag electrode.

关键词： Perovskite solar cells Interfacial degradation Ions migration Photoemission spectroscopy