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Revealing the surface atomic arrangement of noble metal alkane dehydrogenation catalysts by a stepwise reduction-oxidation approach

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Nano Research 2023年第4期16卷 4499-4505页

作者： Chenliang Ye Mao Peng tingting Cui Xinxin tang Dingsheng Wang Miaolun Jiao jeffrey t.miller Yadong Li Department of Chemistry Tsinghua UniversityBeijing 100084China Davidson School of Chemical Engineering Purdue University480 Stadium Mall DriveWest LafayetteIN 47907USA School of Chemical Engineering and technology Tianjin UniversityTianjin 300072China Institute of Microbial Chemistry (BIKAKEN)Tokyo 141-0021Japan

Surface characterization of metal nanoparticles is a critical need in nanocatalysis for in-depth understanding of the structure-function *** surface structure of nanoparticles is often different from the subsurface,and it is challenging to separately characterize the surface and the *** this work,theoretical calculations and extended X-ray absorption fine structure(EXAFS)analysis illustrate that the surface atoms of noble metals(Pt and Pd)are oxidized in the air,while the subsurface atoms are not easily *** advantage of the oxidation properties,we suggest a stepwise reduction-oxidation approach to determine the surface atomic arrangement of noble metal nanoparticles,and confirm the rationality of this approach by identifying the surface structure of typical 2-3 nm Pt and Pd *** reduction-oxidation approach is applied to characterize the surface structure of model Pd-Sb bimetallic catalyst,which illustrates that the surface Pd is well isolated by Sb atoms with short bond distance at 2.70Å,while there are still Pd-Pd bonds in the *** functional theory(DFt)calculations and Pd L edge X-ray absorption near edge structure(XANES)indicate that the isolation of surface Pd significantly decreases the adsorption energies of Pd-hydrocarbon,which leads to the high propylene selectivity and turnover frequency Pd-Sb bimetallic catalyst for propane dehydrogenation.

关键词： surface characterization stepwise reduction-oxidation approach propane dehydrogenation Pd-Sb bimetallic catalyst

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the proximity between hydroxyl and single atom determines the catalytic reactivity of Rh1/CeO_(2) single-atom catalysts

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Nano Research 2024年第1期17卷 397-406页

作者： Danfeng Wu Shuyun Zhou Congcong Du Juan Li Jianyu Huang Hong-xia Shen Abhaya K.Datye Shan Jiang jeffrey t.miller Sen Lin Haifeng Xiong State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China State Key Laboratory of Photocatalysis on Energy and Environment College of ChemistryFuzhou UniversityFuzhou 350002China Clean Nano Energy Center State Key Laboratory of Metastable Materials Science and TechnologyYanshan UniversityQinhuangdao 066004China College of Biology and Chemical Engineering Jiaxing UniversityJiaxing 314000China Department of Chemical&Biological Engineering University of New MexicoAlbuquerqueNM 8731-0001USA Davidson School of Chemical Engineering Purdue UniversityWest LafayetteIN 47907-2100USA Innovation Laboratory for Sciences and technologies of Energy Materials of Fujian Province(IKKEM) Xiamen 361102China Fujian Key Laboratory of Rare-earth Functional Materials Fujian Shanhai Collaborative Innovation Center of Rare-earth Functional MaterialsLongyan 366300China

the local structure of the metal single-atom site is closely related to the catalytic activity of metal single-atom catalysts(SACs).However,constructing SACs with homogeneous metal active sites is a challenge due to the surface heterogeneity of the conventional ***,we prepared two Rh1/CeO_(2)SACs(0.5Rh1/r-CeO_(2)and 0.5Rh1/c-CeO_(2),respectively)using two shaped CeO_(2)(rod and cube)exposing different facets,i.e.,CeO_(2)(111)and CeO_(2)(100).In CO oxidation reaction,the t100 of 0.5Rh1/r-CeO_(2)SACs is 120°C,while the t100 of 0.5Rh1/c-CeO_(2)SACs is as high as 200°*** in-situ CO diffuse reflectance infrared Fourier transform spectroscopy(CO-DRIFtS),we found that the proximity between OH group and Rh single atom on the plane surface plays an important role in the catalytic activity of Rh1/CeO_(2)SAC system in CO *** Rh single atom trapped at the CeO_(2)(111)crystal surface forms the Rh1(OH)adjacent species,which is not found on the CeO_(2)(100)crystal surface at room ***,during CO oxidation,the OH group far from Rh single atom on the 0.5Rh1/c-CeO_(2)disappears and forms Rh1(OH)adjacent species when the temperature is above 150°*** formation of Rh1(OH)adjacentCO intermediate in the reaction is pivotal for the excellent catalytic activity,which explains the difference in the catalytic activity of Rh single atoms on two different CeO_(2)*** formed Rh1(OH)adjacent-O-Ce structure exhibits good stability in the reducing atmosphere,maintaining the Rh atomic dispersion after CO oxidation even when pre-reduced at high temperature of 500°*** functional theory(DFt)calculations validate the unique activity and reaction path of the intermediate Rh1(OH)adjacentCO species *** work demonstrates that the proximity between metal single atom and hydroxyl can determine the formation of active intermediates to affect the catalytic performances in catalysis.

关键词： crystal plane Rh1/CeO_(2)single-atom catalyst proximity of Rh and hydroxyl coordination structure CO oxidation

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two-dimensional atomically thin Pt layers on MXenes: the role of electronic effects during catalytic dehydrogenation of ethane and propane

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Nano Research 2024年第3期17卷 1251-1258页

作者： Zhe Li tobias K.Misicko Fan Yang Xiaopeng Liu Zhenwei Wu Xiaoyang Gao tao Ma jeffrey t.miller Daniela S.Mainardi Collin D.Wick Zhenhua Zeng Yang Xiao Yue Wu Department of Chemical and Biological Engineering Iowa State University618 Bissell RoadAmesIA 50011USA Institute for Micromanufacturing Louisiana Tech University505 Tech DriveRustonLA 71272USA Davidson School of Chemical Engineering Purdue University480 Stadium Mall DriveWest LafayetteIN 47907USA Michigan Center for Materials Characterization University of Michigan2800 Plymouth RdAnn Arbor MI 48109USA College of Engineering and Science Louisiana Tech UniversityRustonLA 71272USA

Atomically thin Pt nanolayers were synthesized on the surface of Mo2tiC2 MXenes and used for the catalytic dehydrogenation of ethane and propane into ethylene and propylene,two important chemicals for the petrochemical *** compared with Pt nanoparticles,the atomically thin Pt nanolayer catalyst showed superior coke-resistance(no deactivation for 24 h),high activity(turnover frequencies(tOFs)of 0.4–1.2 s^(-1)),and selectivity(>95%)toward ethylene and *** unique Pt nanolayer has a similar geometric surface to Pt nanoparticles,enabling the investigations of the electronic effect on the catalytic performance,where the geometric effect is *** is found that the electronic effect plays a critical role in dehydrogenative product selectivity and catalyst *** metal–support interaction is found dependent on the substrate and metal components,providing wide opportunities to explore high-performance MXene-supported metallic catalysts.

关键词： MXene catalysis alkane dehydrogenation nanolayers

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Promoting propane dehydrogenation with CO2 over Ga2O3/SiO2 by eliminating Ga-hydrides

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Chinese Journal of Catalysis 2021年第12期42卷 2225-2233页

作者： Yi Liu Guanghui Zhang Jianyang Wang Jie Zhu Xinbao Zhang jeffrey t.miller Chunshan Song Xinwen Guo State Key Laboratory of Fine Chemicals PSU-DUT Joint Center for Energy ResearchSchool of Chemical EngineeringDalian University of TechnologyDalian 116024LiaoningChina Davidson School of Chemical Engineering Purdue University480 Stadium Mall DriveIN 47907United States Department of Chemistry Faculty of Sciencethe Chinese University of Hong KongShatinNTHong KongChina

Due to the shortage supply of propylene and the development of shale gas,there is increased interest in on-purpose propane dehydrogenation(PDH)technology for propylene ***-based catalysts have great potential in PDH,due to the high activity,low carbon deposit and ***-hydrides formed during PDH reduce the rate,selectivity and yield of *** this contribution,CO_(2)is introduced into PDH as a soft oxidant to eliminate the unfavorable intermediate species Ga^(δ+)-Hx re-generating Ga^(3+)-O pairs,and also minimize coke deposition thereby improving the catalytic *** situ diffuse reflectance infrared Fourier transform(DRIFt)spectroscopy experiments show that CO_(2)can effectively eliminate Ga^(δ+)-*** different temperatures,co-feeding CO_(2)during PDH over Ga_(2)O_(3)/SiO_(2)catalysts with different loadings significantly improves the stability of the conversion and selectivity,especially the latter,and provide a new dimension for improving the performance of PDH process.

关键词： Ga-hydrides Ga_(2)O_(3) CO_(2) Propane dehydrogenation In situ DRIFt

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A facile sulfur-assisted method to synthesize porous alveolate Fe/g-C3N4 catalysts with ultra-small cluster and atomically dispersed Fe sites

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Chinese Journal of Catalysis 2020年第8期41卷 1198-1207页

作者： Sufeng An Guanghui Zhang Jiaqiang Liu Keyan Li Gang Wan Yan Liang Donghui Ji jeffrey t.miller Chunshan Song Wei Liu Zhongmin Liu Xinwen Guo State Key Laboratory of Fine Chemicals PSU-DUT Joint Center for Energy ResearchSchool of Chemical EngineeringDalian University of TechnologyDalian 116024LiaoningChina Stanford Synchrotron Radiation Light Source SLAC National Accelerator Laboratory and Stanford UniversityMenlo ParkCA 94025USA Davidson School of Chemical Engineering Purdue UniversityWest LafayetteIndiana 47907USA EMS Energy Institute PSU-DUT Joint Center for Energy Research and Department of Energy&Mineral EngineeringThe Pennsylvania State UniversityUniversity ParkPennsylvania 16802USA Dalian Institute of Chemical Physics Chinese Academy of SciencesDalian 116023LiaoningChina

Heterogeneous catalysts with ultra-small clusters and atomically dispersed(USCAD)active sites have gained increasing attention in recent ***,developing USCAD catalysts with high-density metal sites anchored in porous nanomaterials is still ***,through the template-free S-assisted pyrolysis of low-cost Fe-salts with melamine(MA),porous alveolate Fe/g-C3N4 catalysts with high-density(Fe loading up to 17.7 wt%)and increased USCAD Fe sites were *** presence of a certain amount of S species in the Fe-salts/MA system plays an important role in the formation of USCAD S-Fe-salt/CN catalysts;the S species act as a"sacrificial carrier"to increase the dispersion of Fe species through Fe-S coordination and generate porous alveolate structure by escaping in the form of SO2 during *** S-Fe-salt/CN catalysts exhibit greatly promoted activity and reusability for degrading various organic pollutants in advanced oxidation processes compared to the corresponding Fe-salt/CN catalysts,due to the promoted accessibility of USCAD Fe sites by the porous alveolate *** S-assisted method exhibits good feasibility in a large variety of S species(thiourea,S powder,and NH4SCN)and Fe salts,providing a new avenue for the low-cost and large-scale synthesis of high-density USCAD metal/g-C3N4 catalysts.

关键词： Sulfur-assisted synthesis Porous alveolate structure Ultra-small cluster and atomically dispersed active sites Fe/g-C3N4 Advanced oxidation processes

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Gold-doping of carbon-supported palladium improves reduction catalysis

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Chinese Journal of Catalysis 2016年第10期37卷 1776-1786页

作者： Yu-lun Fang Kimberly N.Heck Zhun Zhao Lori A.Pretzer Neng Guo tianpin Wu jeffrey t.miller Michael S.Wong 莱斯大学化工与生物分子工程系美国休斯顿77005 莱斯大学化学系美国休斯顿77005 阿贡国家实验室化工科学与工程部美国阿贡IL60439 普渡大学化工系美国西拉斐特莱斯大学土木与环境工程系美国休斯顿77005 菜斯大学材料科学与纳米工程系美国休斯顿77005

Bimetallic palladium-gold （PdAu） catalysts have better catalytic performance than monometallic catalysts for many applications. PdAu catalysts with controlled nanostructures and enhanced activi- ties have been extensively studied but their syntheses require multiple and occasionally complicated steps, In this work, we demonstrated that supported PdAu catalysts could be simply prepared by doping a supported Pd catalyst with gold through wet impregnation and calcination. Resulting PdAu-on-carbon （PdAu/C） catalysts were tested for the room-temperature, aqueous-phase hydro- dech/orination of trichloroethene. the most active PdAu/C catalyst （Pd 1.0 wt%, Au 1.1 wt%, dried/air/H2 process] had an initial turnover frequency （tOF] of 34.0×10^-2 mOItcE mOled-1 S-1, which was 〉15 times higher than monometallic Pd/C （Pd 1,0 wt%, initial tOF of 2.2 ×10^-2 moltCE molpd^-1s^-1）. through X-ray absorption spectroscopy, the gold kept Pd from oxidizing under calcination at 400℃. Probable nanostructure evolution pathways are proposed to explain the observed catalysis,

关键词： Bimetallic catalystPalladiumGoldNanostructuresX-ray absorption spectroscopyExtended X-ray absorption fine structureHydrodechlorinationtrichloroethene

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利用原位X射线光谱技术解析单原子及纳米催化剂构效关系

利用原位X射线光谱技术解析单原子及纳米催化剂构效关系

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第十届全国催化剂制备科学与技术研讨会（成都）

作者：张光辉李克艳 jeffrey t.miller 郭新闻宋春山大连理工大学化工与环境生命学部宾州-大连联合能源研究中心 Davidson School of Chemical Engineering Purdue University EMS Energy Institute Departments of Energy & Mineral Engineering and of Chemical Engineering PSU-DUT Joint Center for Energy Research The Pennsylvania State University State College

随着当代催化科学和原位光谱学技术的发展,催化剂的原位表征在催化研究中的作用越来越重要。我们团队结合多种谱学技术,包括穆斯堡尔谱、X射线光电子能谱、电子顺磁共振谱、原位X射线吸收光谱和原位X射线衍射、球差电镜,并结合密度泛函... 详细信息

随着当代催化科学和原位光谱学技术的发展,催化剂的原位表征在催化研究中的作用越来越重要。我们团队结合多种谱学技术,包括穆斯堡尔谱、X射线光电子能谱、电子顺磁共振谱、原位X射线吸收光谱和原位X射线衍射、球差电镜,并结合密度泛函理论计算细致研究了一系列负载型多相催化剂的结构,明确了催化活性中心的结构,构建了催化剂的构效关系。我们发现:1)石墨相氮化碳(g-CN)锚定的原子簇和单原子铁催化剂可以在温和条件下高效降解各种模型有机污染物。我们通过原位光谱学方法研究了催化剂的组成、

关键词：原位表征 X射线吸收光谱 X射线衍射

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the Association between Problematic Internet Use,Resilience,and Fatigue in First-Year Medical College Students in China:A Moderated Mediation Model

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International Journal of Mental Health Promotion 2025年第1期27卷 51-63页

作者： Xiumei Chen Xiaobing Lu Yufu Ning Lifeng Wang jeffrey H.Gamble Xianhe Chen Xingyong Jiang I-Hua Chen Peijin Lin School of Information Engineering Shandong Youth University of Political ScienceJinan250103China Faculty of Education Qufu Normal UniversityQufu273165China Department of Applied Foreign Language Studies Nanjing UniversityNanjing210023China Department of English National Changhua University of EducationChanghua50007Taiwan No.1 Senior High School Nanchang330000China Yangan Primary School of Qionglai City Qionglai611535China Chinese Academy of Education Big Data Qufu Normal UniversityQufu273165China School of Education and Psychology Minnan Normal UniversityZhangzhou363000China

Background:Resilience is crucial for medical college students to thrive in the highly stressful environment of medical ***,the prevalence of problematic internet use(PIU)in this population may negatively impact their *** study investigated the influence of problematic online gaming(PG)and problematic social media use(PSMU)on the resilience of medical college students in ***:A sample of 5075 first-year medical college students from four Chinese universities was *** served as the independent variable,resilience as the dependent variable,fatigue as the mediator,and PSMU as the *** equation modeling was conducted using LISREL ***,a moderated mediation model was evaluated using the jAMM module in jamovi ***:the study’s findings revealed significant negative correlations between resilience and the variables of PG,PSMU,and *** mediated the relationship between PG and resilience(B=−0.04,95%CI=[−0.05,−0.03]).PSMU moderated the direct relationship between PG and resilience with the interaction term PG×PSMU significant(B=−0.004,t=−6.501,pthe first stage(PG→fatigue)of the mediation with PG×PSMU significant(B=0.055,t=8.351,pthe detrimental effects of PG on resilience were more pronounced among individuals with lower levels of ***:this study concluded that addressing PIU,particularly PG,is essential for fostering resilience in medical college *** PSMU itself is maladaptive,the underlying social media engagement may serve a protective role through social support in mitigating the adverse effects of PG on resilience.

关键词： Problematic internet use problematic online gaming problematic social media use fatigue resilience structural equation modeling conditional mediation

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Inherent Anharmonicity of Harmonic Solids

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Research 2022年第3期2022卷 409-419页

作者： Matthias t.Agne Shashwat Anand G.jeffrey Snyder Department Materials Science and Engineering Northwestern UniversityEvanstonILUSA

Atomic vibrations,in the form of phonons,are foundational in describing the thermal behavior of *** possible frequencies of phonons in materials are governed by the complex bonding between atoms,which is physically represented by a spring-mass model that can account for interactions(spring forces)between the atoms(masses).the lowest-order,harmonic,approximation only considers linear forces between atoms and is thought incapable of explaining phenomena like thermal expansion and thermal conductivity,which are attributed to nonlinear,anharmonic,***,we show that the kinetic energy of atoms in a solid produces a pressure much like the kinetic energy of atoms in a gas *** vibrational or phonon pressure naturally increases with temperature,as it does in a gas and therefore results in a thermal *** thermal expansion thermodynamically defines a Grüneisen parameterγ,which is a typical metric of anharmonicity,we show that even a harmonic solid will necessarily have some anharmonicity.A consequence of this phonon pressure model is a harmonic estimation of the Grüneisen parameter asγ≈(3/2)(3−4x^(2))/(1+2x^(2)),where x=vt/vl is the ratio of the transverse and longitudinal speeds of *** demonstrate the immediate utility of this model by developing a high-throughput harmonic estimate of lattice thermal conductivity that is comparable to other state-of-the-art *** linking harmonic and anharmonic properties explicitly,this study provokes new ideas about the fundamental nature of anharmonicity,while also providing a basis for new material engineering design metrics.

关键词： harmonic phonon linking

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Hydrogen auto-transfer under aerobic oxidative conditions: Efficient synthesis of saturated ketones by aerobic C-C cross-coupling of primary and secondary alcohols catalyzed by a Au_6Pd/resin catalyst

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Chinese Journal of Catalysis 2016年第10期37卷 1764-1770页

作者：周茂祥张磊磊 jeffrey t. miller 杨小峰刘晓艳王爱琴张涛中国科学院大连化学物理研究所催化基础国家重点实验室辽宁大连116023 中国科学院大学北京100049 美国阿贡国家实验室美国阿贡IL60439

Au and Au-containing bimetallic nanoparticles are promising catalysts for the green synthesis of fine chemicals. Here, we used a Au6Pd/resin catalyst for the aerobic C-C cross-coupling of primary and secondary alcohols to produce higher ketones under mild conditions. this is of importance to the construction of a C-C bond. Various substrates were used in the reaction system, and moderate to good yields were obtained. the catalysts can be reused at least five times without decrease of yield. the control experiment and XAFS characterization results showed that hydrogen au- to-transfer occurred on metallic Pd sites even under oxidative conditions. On alloying with Au, the Pd sites became resistant to oxidation and readily abstracted the β-H of the alcohols and transferred the hydride to the C=C bond in the reaction intermediate to give the saturated product.

关键词： Au-Pd alloysC-C coupling reactionOxidation of alcoholsHydrogen auto-transferOxidation-resistant

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