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co oxidation under lean and stoichiometric conditions over ceriazirconia with very low metal contents(Cu,co,Ag and Pt)

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Journal of Rare Earths 2024年第9期42卷 1669-1681,I0002页

作者： J.C.Martínez-Munuera M.P.Yeste A.García-García MCMA Group Department of Inorganic Chemistry and Institute of MaterialsUniversity of AlicanteCarretera de San Vicente del Raspeig s/n03690San Vicente del RaspeigAlicanteSpain Solid Chemistry and Catalysis Group Department of Materials ScienceMetallurgic Engineering and Inorganic ChemistryInstitute of Electronic Microscopy and Materials ResearchUniversity of CádizAp.40E-11510Puerto RealCádizSpain

In this work,several ceria-zirconia based catalysts with very lo w(and equimolar) metal contents were prepared,characterised and tested for the co oxidatio n reaction(under lean and stoichiometric conditions),trying to emulate those conditions found in a diesel oxidation catalyst(DOC) system from a diesel engine and those encountered under gasoline exhaust(λ=1).The metals chosen are Cu,co,Ag and Pt(as a reliable benchmark).The results reveal enormous differences among reducibility and catalytic activity despite quite similar structural and textural properties of the catalysts,showing differences among dispersion(Ag-catalyst seems to present a low level of dispersion).This catalyst seems to be characterised,as well,by a strong electronic interaction between Ce and Ag centres which is suggested to yield an improved reducibility under H_(2)-TPR ***,the order in catalytic activity(Cu>Ag>co≈Pt>>support) seems not to follow the order found in reducibility and the Cu-catalyst seems to be the most active independently on the reaction conditions,yielding nearly overlapped co oxidation catalytic *** restingly,a stro ng correlation between the catalytic activity under the two conditions tested and the OSC values of the Ce_(0.8)Zr_(0.2)O_(2)-supported metal catalysts is ***,OSC parameter measured at 150℃ can be used as a relevant descriptor to evaluate the co oxidation activity at low and medium conversions for the investigated catalysts,much better than the H_(2)-TPR measurements.

关键词： co oxidation Low metal content Ceria-zirconia copper species OSC parameter Rare earths

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Tuning interaction strength between CeO_(2) and iridium to promote co oxidation over Ir/TiO_(2)

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Journal of Rare Earths 2024年第4期42卷 651-659页

作者： Lu Dai Binghua Li Yuhan Peng Xianwei Hao Runquan Xuan Hua Huang Yiming Bi Liping Xu Yanhui Zhang Yun Guo Fangqi Du Li Wang Hui Wang Technology Center China Tobacco Zhejiang Industrial Co.Ltd.Hangzhou310024China Research Institute of Industrial Catalysis East China University of Science and TechnologyShanghai200237China

The interaction between support and noble metal plays a crucial role in heterogeneous catalysis ***,how to tune metal support interactions to optimize the activity still needs further ***_(2) was introduced to promote co oxidation ove r Ir/TiO_(2) by adjusting the interaction strength between iridium(Ir)and CeO_(2).The strong interaction between Ir and CeO_(2) blocks co adsorption and causes low co oxidation ***,introducing CeO_(2) on Ir/TiO_(2) produces localized interaction between Ir and CeO_(2),which can tune the surface electronic state of Ir,so a"volcano curve"relationship between co oxidation activity and electronic state is *** amount of CeO_(2) on Ir/TiO_(2)(Ir/Ce_(0.2)Ti)leads to co complete oxidization at 22℃,and a new pathway for co oxidation was *** study demonstrates that the utilization of tuning interaction strength between active metal and support is a potential method to increase the catalytic activity.

关键词： co oxidation CeO_(2) Localized interaction Interaction strength Supported Ir catalysts Rareearths

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Investigating the impact of dynamic structural changes of Au/rutile catalysts on the catalytic activity of co oxidation

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Carbon Energy 2024年第4期6卷 222-232页

作者： Xiaochun Hu Qianwenhao Fan Mingwu Tan Yuqing Luo Xianyue Wu Manoel Y.Manuputty Jie Ding Tej S.Choksi Markus Kraft Rong Xu Zhiqiang Sun Wen Liu School of Energy Science and Engineering Central South UniversityChangshaChina School of Chemistry Chemical Engineering and BiotechnologyNanyang Technological UniversitySingaporeSingapore Cambridge Centre for Advanced Research and Education SingaporeSingapore Institute of Sustainability for Chemicals Energy and EnvironmentJurong IslandSingapore college of Chemistry and Chemical Engineering Central South UniversityChangshaChina Department of Chemical Engineering and Biotechnology University of CambridgeCambridgeUK

The surface properties of oxidic supports and their interaction with the supported metals play critical roles in governing the catalytic activities of oxide‐supported metal *** metals are supported on reducible oxides,dynamic surface reconstruction phenomena,including strong metal–support interaction(SMSI)and oxygen vacancy formation,complicate the determination of the structural–functional relationship at the active ***,we performed a systematic investigation of the dynamic behavior of Au nanocatalysts supported on flame‐synthesized TiO_(2),which takes predominantly a rutile phase,using co oxidation above room temperature as a probe *** analysis conclusively elucidated a negative correlation between the catalytic activity of Au/TiO_(2) and the oxygen vacancy at the Au/TiO_(2) *** the reversible formation and retracting of SMSI overlayers have been ubiquitously observed on Au/TiO_(2) samples,the catalytic consequence of SMSI remains *** functional theory suggests that the electron transfer from TiO_(2) to Au is correlated to the presence of the interfacial oxygen vacancies,retarding the catalytic activation of co oxidation.

关键词： co oxidation electronic metal-support interactions flame‐synthesis metal-support interactions oxygen vacancy strong metal-support interaction

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Evolution of copper species during heat treatment and its effect on co oxidation reaction on CuCeZrO_(y) catalyst synthesized by a facile solvent-free route

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Journal of Rare Earths 2024年第4期42卷 660-667页

作者： Guangying Fu Dongsen Mao Jun Yu Qiangsheng Guo School of Chemical and Environmental Engineering Shanghai Institute of TechnologyShanghai21418 China The ZeoMat Group Qingdao Institute of Bioenergy and Bioprocess TechnologyCASQingdao26611China

Several ternary oxides CuCeZrO_(y)(CCZ)were synthesized by a facile grinding method followed by calcination at high temperatures,and used as catalysts for co oxidation at low *** influences of calcination temperature(400-600℃)on the physicochemical properties of the assynthesized ternary oxides were investigated by thermogravimetric analysis/differential scanning calorimetry(TGA/DSC),X-ray diffraction(XRD),transmission electron microscopy(TEM),Raman,inductively coupled plasma-optical emission spectrometry(ICP-OES),N_(2) adsorption,H_(2)-temperature programmed reduction(H_(2)-TPR),and X-ray photoelectron spectroscopy(XPS)*** results show that the increase in calcination temperature from 400 to 500℃is conducive to the high dispersion of CuOx on catalyst surface and the incorporation of Cu species into the support to form the Cu-Ce-Zr-O solid *** raising of calcination temperature from 500 to 600℃,however,leads to the segregation of Cu species from the solid solution to aggregate on support surface and growth of highly dispersed CuOx *** highest catalytic activity is acquired over the CCZ calcined at 500℃,which can be ascribed to the largest contents of Cu+species and oxygen vacancies owing to the formation of the maximum amount of Cu-Ce-Zr-O solid solution.

关键词： CuCeZrO_(y)catalyst co oxidation Calcination temperature Grinding method Oxalate precursor Rare earths

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Interplay between geometric and electronic structures of Pt entities over TiO_(2) for co oxidation

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Science China Chemistry 2024年第2期67卷 705-714页

作者： Xixiong Zhang Wen Shi Shaobo Han Yong Li Wenjie Shen School of Chemistry Dalian University of TechnologyDalian116024China State Key Laboratory of Catalysis Dalian Institution of Chemical PhysicsChinese Academy of SciencesDalian116023China

Monodispersed Pt colloids with a mean size of 2 nm were deposited uniformly on the {110} facets of a rod-shaped rutile TiO_(2),forming a well-defined Pt/TiO_(2) *** treatment of this precursor at elevated temperatures re-dispersed the Pt particles into clusters and ***-calcination at 673 K partially oxidized the Pt particle surface,while calcination at 773 K yielded Pt Oxclusters of 1.6 nm in 7–8 atomic *** calcination at 873 K formed a mixture of raft-like PtO_(x) clusters(1.6 nm,1–2 atomic layers) and cationic *** tested for co oxidation at 373 K,the Pt particles showed a higher activity than the Pt Oxclusters,whereas the cationic single-atoms were much less *** H_(2)-reduction at 473 K converted the partially oxidized Pt particles into the metallic species,but they were encapsulated by TiO_(2)–xoverlayers because of the strong metal–support interactions,which decreased the activity dramatically.H_(2)-reduction of the PtO_(x) clusters at473 K enhanced the fraction of metallic Pt species without changing the size and geometry,and promoted the activity substantially.H_(2)-treatment of Pt single-atoms at 473 K increased the activity only moderately because most Pt species still kept at cationic *** results straightforwardly differentiated the catalytic behavior of Pt particles,clusters and single-atoms at the same metal loading and over the same TiO_(2) support,and further demonstrated that the electronic structures of Pt entities played a decisive role in the catalytic oxidation,in addition to the specified sizes.

关键词： Pt/TiO_(2)catalyst size effect Pt clusters active sites electronic structures co oxidation

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Insights into the interface of Nico_(2)O_(4) spinel/LacoO_(3) perovskite nano-composite for co and soot oxidation

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Journal of Environmental Sciences 2024年第4期138卷 339-349页

作者： Neha Harshita Singh Satya Vir Singh Department of Chemical Engineering Indian Institute of Technology(BHU)Varanasi221005India Department of Botany Institute of ScienceBanaras Hindu UniversityVaranasi221005India

In the quest for the development of thermally stable,highly active and low-cost catalysts for use in catalyzed diesel particulate filter,nano-composites are new areas of ***,we reported the easy synthesis of spinel Nico_(2)O_(4)/perovskite LacoO_(3) nano-composite,and its individual oxides Nico_(2)O_(4)and LacoO_(3) for *** detailed insights into the physio-chemical characteristics of formed Nico_(2)O_(4)/LacoO_(3) nano-composite were done based on various characterization analysis such as X-ray diffraction(XRD),Fourier transform infrared(FT-IR),N_(2) physiosorption,scanning electron microscopy-energy dispersive spectroscopy(SEM-EDX),transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS).The characterization analysis of Nico_(2)O_(4)/LacoO_(3) revealed the successful formation of a chemical interface possessing strong interfacial interaction,resulting in desirable physicochemical characteristics such as small crystallite size,abundant mesoporosity,high specific surface area and activation of surface lattice *** to the desirable characteristics,the activity results over Nico_(2)O_(4)/LacoO_(3) nano-composite showed the excellent co oxidation performance and high soot oxidation activity,recyclability and thermal *** work mainly attempts to emphasize the effectiveness of the facile,inexpensive and conventionally used precipitation method for the successful formation of highly efficient nano-composites.

关键词： LacoO_(3) Nico_(2)O_(4) Spinel/perovskite co oxidation Soot oxidation Chemical interface

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co oxidation by Neutral Gold-Vanadium Oxide Clusters

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Chinese Journal of Chemical Physics 2019年第2期32卷 207-212,I0002,I0006-I0011页

作者： Shu-hua Ou Jiao-jiao Chen Xiao-na Li Li-na Wang Tong-mei Ma Sheng-gui He School of Chemistry and Chemical Engineering South China University of Technology Guangzhou 510641 China State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China Beijing National Laboratory for Molecular Sciences CAS Research/Education Center for Excellence in Molecular Sciences Beijing 100190 China

oxidation of co by gas-phase atomic clusters is being actively studied to understand the molecular-level mechanisms of heterogeneous co oxidation over related catalytic surfaces. However, it is experimentally challenging to study co oxidation by neutral heteronuclear metal oxide clusters because of the difficulty of cluster ionization and detection without fragmentation. Herein, the neutral AuVO2-4 clusters were experimentally generated and their reactions with co and O2 were studied. The experimental results showed that co adsorption is the dominant channel on the interactions of AuVO4 and AuVO3 with co, and AuVO2 can pick up an O2 molecule to generate AuVO4. Theoretical studies indicated that the oxidation of the trapped co in AuVO3,4co into co2 is exothermic while the reaction barriers have to be overcome at the elevated temperatures. A catalytic cycle for co oxidation by AuVO2-4 is proposed.

关键词： co oxidation Neutral clusters Gold Mass spectrometry Theoretical calculations

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co oxidation and 4-nitrophenol reduction over ceria-promoted platinum nanoparticles impregnated with ZSM-5 zeolite

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Journal of Rare Earths 2022年第8期40卷 1247-1254页

作者： Zeinhom M.El-Bahy Mohammed T.Alotaibi Salah M.El-Bahy Department of Chemistry Faculty of ScienceAl-Azhar UniversityNasr City11884CairoEgypt Department of Chemistry Turabah University CollegeTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia

Active new ceria-promoted platinum supported on ZSM-5 catalysts were prepared and characterized by X-ray diffraction(XRD),Fourier transform infrared spectra(FTIR),transform electron microscopy(TEM),temperature programmed desorption(TPD),and FTIR of co *** samples were prepared by the incipient wetness impregnation method and calcined at 500℃.The XRD patterns and FTIR spectra prove that the zeolite framework is kept unaltered after metal *** images prove the presence of Pt nanoparticles with particle size starting from 14 to 27 *** FTIR data suggest the formation of Pt-O-Ce ***-situ FTIR of co adsorption over reduced samples proves the presence of Pt~0 only,and no Pt^(n+)-co species are *** prepared catalysts were tested in both oxidation reaction(co oxidation) in the gas phase and in reduction reaction(4-nitrophenol reduction) in the aqueous ***,co oxidation by O_(2) results in the formation of a co_(2) peak at 2347 cm^(-1) as the only co oxidation product in the studied frequency *** intensity of the co_(2) peak increases after the addition of Ce,and it is 4 times higher in Pt_(1) Ce_(0.5)ZSM-5 than that in the Ce-free *** to the FTIR data and previous reports,the increase in the catalytic activity may be due to the formation of Pt-O-Ce ***,Ce-promoted Pt_(1) ZSM5 also exhibits enhanced catalytic activity towards the reduction of 4-nitrophenol to 4-aminophenol by NaBH_(4) in the aqueous *** first-order rate constant of the reduction increases ≈13 times after incorporating equal ratios of Pt and Ce(Pt_(1) Ce_(1)ZSM-5),and the activation energy(E_(a)) decreases to 40% of that in the reaction over Pt_(1) ZSM-5.

关键词： 4-Nitrophenol co oxidation TPD-co Platinum-cerium ZSM-5 Rare earths

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co oxidation over CuO catalysts supported on CeO_2-ZrO_2 prepared by microwave-assisted co-precipitation:The influence of CuO content

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Journal of Rare Earths 2014年第2期32卷 117-123页

作者：杨志强毛东森郭晓明卢冠忠 Research Institute of Applied Catalysis School of Chemical and Environmental EngineeringShanghai Institute of Technology

CeO2-ZrO2 mixed oxide （Ce0.6Zr0.402） prepared by microwave-assisted heating co-precipitation was used as a support to prepare a series of CuO/Ce0.6Zr0.402 catalysts with various CuO contents （0 wt.%-1 5 wt.%） via the method of incipient-wetness im- pregnation. The obtained CuO/Ce0.6Zr0.402 samples were characterized by N2 adsorption, XRD, Raman, TEM and H2-TPR technolo- gies, and their catalytic activities for co oxidation were investigated. The results showed that the activity of CuO/Ce0.6Zr0.402 catalyst was strongly influenced by the content of CuO, and the catalyst with 10 wt.% CuO exhibited the best catalytic activity in co oxida- tion, which could be attributed to the high dispersion and reducibility of CuO, and high oxygen vacancy concentration in the catalyst.

关键词： cerium-zirconium mixed oxide copper oxide microwave heating co oxidation rare earths

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co oxidation on MXene(Mo_(2)CS_(2)) supported single-atom catalyst: A termolecular Eley-Rideal mechanism

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中国化学快报：英文版 2023年第2期34卷 519-528页

作者： Shamraiz Hussain Talib Zhansheng Lu Beenish Bashir Sajjad Hussain Khalil Ahmad Salahuddin Khan Sajjad Haider Zongxian Yang Kersti Hermansson Jun Li School of Physics Henan Normal UniversityXinxiang 453007China Department of Chemistry and Key Laboratory of Organic Optoelectronics&Molecular Engineering of Ministry of Education Tsinghua UniversityBeijing 100084China Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China School of Chemistry Minhaj UniversityLahore 54000Pakistan Department of Chemistry Mirpur University of Science and Technology(MUST)MirpurAJK 10250Pakistan college of Engineering King Saud UniversityPO Box 800Riyadh 11421Saudi Arabia Chemical Engineering Department College of EngineeringKing Saud UniversityPO Box 800Riyadh 11421Saudi Arabia Department of Chemistry-Ångström Uppsala UniversityBox 538Uppsala 75121Sweden Department of Chemistry Southern University of Science and TechnologyShenzhen 518055China

Finding transition metal catalysts for effective catalytic conversion of co to co_(2)has attracted much *** as a new 2D layered material of early transition metal carbides,nitrides,and carbo-nitrides is a robust support for achoring metal *** this study,the electronic structure,geometries,thermodynamic stability,and catalytic activity of MXene (Mo_(2)CS_(2)) supported single noble metal atoms (NM=Ru,Rh,Pd,Ir,Pt and Au) have been systematically examined using first-principles calculations and ab initio molecular dynamic (AIMD) ***,AIMD simulations and phonon spectra demonstrate the dynamic and thermal stabilities of Mo_(2)CS_(2)*** likely reaction pathways,LangmuirHinshelwood (LH),Eley-Rideal (ER),and Termolecular Eley–Rideal (TER) for co oxidation on the Ru1-and Ir_(1)@Mo_(2)CS_(2)SACs,have been studied in *** is found that co oxidation mainly proceeds via the TER mechanism under mild reaction *** corresponding rate-determining steps are the dissociation of the intermediate (Oco-Ru_(1)-Oco) and formation of Oco-Ir_(1)-Oco *** downshift d-band center of Ru1-and Ir_(1)@Mo_(2)CS_(2)help to enhance activity and improve catalytst ***,a microkinetic study predicts a maximum co oxidation rate of 4.01×10^(2)s^(-1)and 4.15×10^(3)s^(-1)(298.15K) following the TER pathway for the Ru_(1)-and Ir_(1)@Mo_(2)CS_(2)catalysts,*** work provides guideline for fabricating and designing highly efficient SACs with superb catalyts using MXene materials.

关键词： co oxidation Quantum chemical study 2D MXene monolayer M1@Mo_(2)CS_(2) Termolecular Eley–Rideal Single-atom catalysis

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