Catalysis Structure & Reactivity最新文献_第6页

Pd deposition on TiO2(110) and nanoparticle encapsulation 钯在TiO2(110)上沉积及纳米颗粒包封

Catalysis Structure & Reactivity Pub Date : 2015-07-03 DOI: 10.1179/2055075815Y.0000000008

M. Bowker, R. Sharpe

引用次数: 8

A combined approach for deposition and characterization of atomically engineered catalyst nanoparticles 原子工程催化剂纳米颗粒沉积和表征的综合方法

Catalysis Structure & Reactivity Pub Date : 2015-07-03 DOI: 10.1179/2055075815Y.0000000006

Qifeng Yang, D. Joyce, S. Saranu, G. Hughes, A. Varambhia, Michael P. Moody, P. Bagot

{"title":"A combined approach for deposition and characterization of atomically engineered catalyst nanoparticles","authors":"Qifeng Yang, D. Joyce, S. Saranu, G. Hughes, A. Varambhia, Michael P. Moody, P. Bagot","doi":"10.1179/2055075815Y.0000000006","DOIUrl":"https://doi.org/10.1179/2055075815Y.0000000006","url":null,"abstract":"The structure and composition of catalytic silver nanoparticles (Ag-NPs) fabricated through a novel gas condensation process has been characterized by Scanning Electron Microscopy (SEM) and Atom Probe Tomography (APT). SEM was used to confirm the number density and spatial distribution of Ag-NPs deposited directly onto standard silicon microposts used for APT experiments. Depositing nanoparticles (NPs) directly by this method eliminates the requirement for focussed ion beam (FIB) liftout, significantly decreasing APT specimen preparation time and enabling far more NPs to be examined. Furthermore, by encapsulating deposited particles before final FIB sharpening, the APT reconstruction methodologies have been improved over prior attempts, as demonstrated by comparison to the SEM data. Progress in these areas is vital to enable large-scale catalyst research efforts using APT, a technique, which offers significant potential to examine the detailed atomic-scale chemistry in a wide variety of catalytic NPs. Graphical Abstract","PeriodicalId":43717,"journal":{"name":"Catalysis Structure & Reactivity","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1179/2055075815Y.0000000006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"65872286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 14

Effect of acidity and texture of micro-, mesoporous and hybrid micromesoporous materials on the synthesis of paramenthanic diol exhibiting anti-Parkinson activity 微孔、介孔和杂化微介孔材料的酸度和结构对合成具有抗帕金森活性的副甲基二醇的影响

Catalysis Structure & Reactivity Pub Date : 2015-07-03 DOI: 10.1179/2055075815Y.0000000009

A. Torozova, P. Mäki-Arvela, N. Shcherban, N. Kumar, A. Aho, M. Štekrová, K. Maduna Valkaj, P. Sinitsyna, S. Filonenko, P. Yaremov, V. Ilyin, K. Volcho, N. Salakhutdinov, D. Murzin

{"title":"Effect of acidity and texture of micro-, mesoporous and hybrid micromesoporous materials on the synthesis of paramenthanic diol exhibiting anti-Parkinson activity","authors":"A. Torozova, P. Mäki-Arvela, N. Shcherban, N. Kumar, A. Aho, M. Štekrová, K. Maduna Valkaj, P. Sinitsyna, S. Filonenko, P. Yaremov, V. Ilyin, K. Volcho, N. Salakhutdinov, D. Murzin","doi":"10.1179/2055075815Y.0000000009","DOIUrl":"https://doi.org/10.1179/2055075815Y.0000000009","url":null,"abstract":"Abstract Microporous, mesoporous and new hybrid materials were studied in verbenol oxide isomerization for the synthesis of biologically active substance with anti-Parkinson activity. H-Si-MCM-41, H-Al-MCM-41, H-Al-MCM-48, H-Beta-25 and H-Beta-300 were compared with hybrid materials. The latter with a zeolite-like micro-mesoporous structure were characterized and evaluated for their catalytic activity for the first time. The approach of dual templating for synthesis of new materials was applied in this work to combine properties of Beta-zeolites and mesoporous cellular foams. The selectivity to the target product was the highest over microporous mild acidic H-Beta-300 and hybrid ZF-100, with also mild acidity and even absence of strong acid sites. Selectivity at 97% and 99% of conversion was 61% and 59% for H-Beta-300 and hybrid ZF-100, respectively.","PeriodicalId":43717,"journal":{"name":"Catalysis Structure & Reactivity","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1179/2055075815Y.0000000009","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"65872374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Investigation of support effect on CO adsorption and CO + O2 reaction over Ce1 − x − yMxCuyO2 − δ (M = Zr, Hf and Th) catalysts by in situ DRIFTS Ce1−x−yMxCuyO2−δ (M = Zr, Hf和Th)催化剂上载体对CO吸附和CO + O2反应的影响

Catalysis Structure & Reactivity Pub Date : 2015-05-05 DOI: 10.1179/2055075815Y.0000000004

Tinku Baidya, P. Bera

引用次数: 11

Re-dispersion of gold supported on a ‘mixed’ oxide support 在“混合”氧化物支架上支撑的金的再分散

Catalysis Structure & Reactivity Pub Date : 2015-04-28 DOI: 10.1179/2055075815Y.0000000005

K. Morgan, R. Burch, M. Daous, J. Delgado, A. Goguet, C. Hardacre, L. Petrov, D. Rooney

引用次数: 3

Selectivity determinants for dual function catalysts: applied to methanol selective oxidation on iron molybdate 双功能催化剂的选择性决定因素:应用于钼酸铁上甲醇选择性氧化

Catalysis Structure & Reactivity Pub Date : 2015-04-01 DOI: 10.1179/2055075815Y.0000000002

M. Bowker, M. House, Abdulmohsen A. Alshehri, C. Brookes, E. Gibson, P. Wells

引用次数: 15

Reduction properties of Ce in CeOx/Pt/Al2O3 catalysts CeOx/Pt/Al2O3催化剂中Ce的还原性能

Catalysis Structure & Reactivity Pub Date : 2015-04-01 DOI: 10.1179/2055075815Y.0000000001

P. Wells, E. Crabb, C. R. King, S. Fiddy, A. Amieiro-Fonseca, D. Thompsett, A. Russell

引用次数: 6

Stabilization of iron by manganese promoters in uniform bimetallic FeMn Fischer–Tropsch model catalysts prepared from colloidal nanoparticles 由胶体纳米颗粒制备的均匀双金属FeMn fisher - tropsch模型催化剂中锰促进剂对铁的稳定作用

Catalysis Structure & Reactivity Pub Date : 2015-04-01 DOI: 10.1179/2055075815Y.0000000003

M. Dad, H. Fredriksson, J. van de Loosdrecht, P. Thüne, J. Niemantsverdriet

{"title":"Stabilization of iron by manganese promoters in uniform bimetallic FeMn Fischer–Tropsch model catalysts prepared from colloidal nanoparticles","authors":"M. Dad, H. Fredriksson, J. van de Loosdrecht, P. Thüne, J. Niemantsverdriet","doi":"10.1179/2055075815Y.0000000003","DOIUrl":"https://doi.org/10.1179/2055075815Y.0000000003","url":null,"abstract":"Abstract A systematic study was carried out to investigate the response of monodisperse supported Fe and FeMn nanoparticles to treatments in O2, H2 and H2/CO at temperatures between 270 and 400°C. Uniform size (7–14 nm), Fe and mixed FeMn nanoparticles were synthesised by applying thermal decomposition of Fe- and Mn-oleate complexes in a high boiling point solvent. By combining X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and energy-dispersive X-ray (EDX) analysis, the phase composition and morphology of the model catalysts were studied. Energy-dispersive X-ray analysis shows that the catalyst particles have the expected composition of Fe and Mn. Well-defined crystallite phases [maghemite (γ-Fe2O3) and mixed FeMn-spinel] were observed after calcination at 350°C in Ar/O2 using XPS analysis. Upon subsequent treatments in H2 and H2/CO the crystal phases changed from maghemite (γ-Fe2O3) to metallic Fe, Fe carbide and graphitic C. Using Mn as a promoter influences the nanoparticle size achieved during the fabrication of Fe nanoparticles and improves their stability against morphological change and agglomeration during reduction and Fischer–Tropsch synthesis conditions.","PeriodicalId":43717,"journal":{"name":"Catalysis Structure & Reactivity","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1179/2055075815Y.0000000003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"65872080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 21

Determining surface structure and stability of ε-Fe2C, χ-Fe5C2, θ-Fe3C and Fe4C phases under carburization environment from combined DFT and atomistic thermodynamic studies 用DFT和原子热力学相结合的方法测定渗碳环境下ε-Fe2C、χ-Fe5C2、θ-Fe3C和Fe4C相的表面结构和稳定性

Catalysis Structure & Reactivity Pub Date : 2015-02-01 DOI: 10.1179/2055075814Y.0000000007

Shu Zhao, Xingwu Liu, Chun-fang Huo, Yong-wang Li, Jianguo Wang, H. Jiao

{"title":"Determining surface structure and stability of ε-Fe2C, χ-Fe5C2, θ-Fe3C and Fe4C phases under carburization environment from combined DFT and atomistic thermodynamic studies","authors":"Shu Zhao, Xingwu Liu, Chun-fang Huo, Yong-wang Li, Jianguo Wang, H. Jiao","doi":"10.1179/2055075814Y.0000000007","DOIUrl":"https://doi.org/10.1179/2055075814Y.0000000007","url":null,"abstract":"Abstract The chemical–physical environment around iron based FTS catalysts under working conditions is used to estimate the influences of carbon containing gases on the surface structures and stability of ε-Fe2C, χ-Fe5C2, θ-Fe3C and Fe4C from combined density functional theory and atomistic–thermodynamic studies. Higher carbon content gas has higher carburization ability; while higher temperature and lower pressure as well as higher H2/CO ratio can suppress carburization ability. Under wide ranging gas environment, ε-Fe2C, χ-Fe5C2 and θ-Fe3C have different morphologies, and the most stable non-stoichiometric termination changes from carbon-poor to carbon-rich (varying surface Fe/C ratio) upon the increase in ΔμC. The most stable surfaces of these carbides have similar surface bonding pattern, and their surface properties are related to some common phenomena of iron based catalysts. For these facets, χ-Fe5C2-(100)-2.25 is most favored for CO adsorption and CH4 formation, followed by θ-Fe3C-(010)-2.33, ε-Fe2C-(121)-2.00 and Fe4C-(100)-3.00, in line with surface work function and the charge of the surface carbon atoms.","PeriodicalId":43717,"journal":{"name":"Catalysis Structure & Reactivity","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1179/2055075814Y.0000000007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"65871785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 50

Development and characterization of thermally stable supported V–W–TiO2 catalysts for mobile NH3–SCR applications 用于移动NH3-SCR的热稳定负载型V-W-TiO2催化剂的研制与表征

Catalysis Structure & Reactivity Pub Date : 2015-02-01 DOI: 10.1179/2055075814Y.0000000005

A. Beale, I. Lezcano‐González, T. Maunula, R. Palgrave

{"title":"Development and characterization of thermally stable supported V–W–TiO2 catalysts for mobile NH3–SCR applications","authors":"A. Beale, I. Lezcano‐González, T. Maunula, R. Palgrave","doi":"10.1179/2055075814Y.0000000005","DOIUrl":"https://doi.org/10.1179/2055075814Y.0000000005","url":null,"abstract":"Abstract Vanadium based catalysts supported on a mixture of tungsten and titanium oxide (V2O5/WO3–TiO2) are known to be highly active for ammonia selective catalytic reduction (NH3–SCR) of NOx species for heavy-duty mobile applications. However they are also known to be sensitive to high temperatures which leads to both sintering of the anatase TiO2 support and a first order phase transition to rutile at temperatures >600°C. Here we report our attempts to use SiO2 to stabilize the TiO2 anatase phase and to compare its catalytic activity with that of a non-stabilized V2O5/WO3–TiO2 catalyst after thermal aging up to 800°C. Detailed characterization using spectroscopic (Raman, UV–vis, X-ray absorption spectroscopy), scattering and techniques providing information on the catalytic surface (Brunauer–Emmet–Teller, NH3 adsorption) have also been performed in order to understand the impact of high temperatures on component speciation and the catalytic interface. Results show that non-stabilized V2O5/WO3–TiO2 catalysts are initially stable after thermal aging at 600°C but on heating above this temperature a marked drop in catalytic activity is observed as a result of sintering and phase transformation of Anatase into Rutile TiO2 and phase segregation of initially highly dispersed WO3 and polymeric V2O5 into monoclinic WO3 and V2O3 crystallites. Similar behavior was observed for the 4–5 wt-% of SiO2-stabilised sample after aging above 700°C, importantly therefore, offset by some ∼100°C in comparison to the unstabilised sample.","PeriodicalId":43717,"journal":{"name":"Catalysis Structure & Reactivity","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1179/2055075814Y.0000000005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"65871647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 29