1,721,710 research outputs found
Environment effects in heterogeneous catalysis: from nanoparticles to single atoms
No full textSSCI-VIDE+ECI2D+LPIInternational audienceRecent progress in nanomaterials preparation, characterization and theoretical modeling opens the way to tailoring catalysts and understanding their operating mode at the atomic level. Many strategies are possible for improving the performances of metal-based catalysts, e.g., as done in our laboratory, through the use of alloy phases (noble metal nanoalloys1 and non-noble intermetallics2) and/or reducible oxide supports (e.g. TiO2 3 and CeO2 4). It will be shown that the targeted catalytic processes (selective hydrogenations and preferential CO oxidation) all benefit from metal-metal and/or metal-oxide synergies. As these reactions involve hydrogen-rich environments, hydrogen absorption in the metal lattice can have a drastic influence on the catalytic properties.5,6 Moreover, advanced microscopy and spectroscopy techniques reveal additional major effects of the gaseous atmosphere and the support on the catalyst phase, such as changes in nanoparticle morphology, chemical arrangement and oxidation state (Fig. 1).4,7 Finally, as will be shown from operando techniques in the prototypical case of CO oxidation over Pt/-Al2O3, the influence of the thermochemical environment is even more dramatic for the stability of recently emerging “singe-atom catalysts”.8,9 Confronting experimental observations with computer simulations enables us to identify the key structural drivers and elucidate the reaction mechanisms.2,7,9,10(1) Piccolo, L. Surface Studies of Catalysis by Metals: Nanosize and Alloying Effects. In Nanoalloys: Synthesis, Structure and Properties; Alloyeau, D., Mottet, C., Ricolleau, C., Eds.; Engineering Materials; Springer London, 2012; pp 369–404.(2) Piccolo, L.; Chatelier, C.; Weerd, M.-C. D.; Morfin, F.; Ledieu, J.; Fournée, V.; Gille, P.; Gaudry, E. Sci. Technol. Adv. Mater. 2019, 20, 557–567.(3) Nguyen, T.-S.; Laurenti, D.; Afanasiev, P.; Konuspayeva, Z.; Piccolo, L. J. Catal. 2016, 344, 136–140.(4) Morfin, F.; Nguyen, T.-S.; Rousset, J.-L.; Piccolo, L. Appl. Catal. B 2016, 197, 2–13.(5) Zlotea, C.; Morfin, F.; Nguyen, T.-S.; Nguyen, N.-T.; Nelayah, J.; Ricolleau, C.; Latroche, M.; Piccolo, L. Nanoscale 2014, 6, 9955–9959.(6) Zlotea, C.; Oumellal, Y.; Provost, K.; Morfin, F.; Piccolo, L. Appl. Catal. B 2018, 237, 1059–1065.(7) Piccolo, L.; Li, Z. Y.; Demiroglu, I.; Moyon, F.; Konuspayeva, Z.; Berhault, G.; Afanasiev, P.; Lefebvre, W.; Yuan, J.; Johnston, R. L. Sci. Rep. 2016, 6, 35226.(8) Dessal, C.; Len, T.; Morfin, F.; Rousset, J.-L.; Aouine, M.; Afanasiev, P.; Piccolo, L. ACS Catal. 2019, 9, 5752–5759.(9) Dessal, C.; Sangnier, A.; Chizallet, C.; Dujardin, C.; Morfin, F.; Rousset, J.-L.; Aouine, M.; Bugnet, M.; Afanasiev, P.; Piccolo, L. Nanoscale 2019, 11, 6897–6904.(10) Goyhenex, C.; Piccolo, L. Phys. Chem. Chem. Phys. 2017, 19, 32451–32458
Environment effects in heterogeneous catalysis: from nanoparticles to single atoms
No full textSSCI-VIDE+ECI2D+LPIInternational audienceRecent progress in nanomaterials preparation, characterization and theoretical modeling opens the way to tailoring catalysts and understanding their operating mode at the atomic level. Many strategies are possible for improving the performances of metal-based catalysts, e.g., as done in our laboratory, through the use of alloy phases (noble metal nanoalloys1 and non-noble intermetallics2) and/or reducible oxide supports (e.g. TiO2 3 and CeO2 4). It will be shown that the targeted catalytic processes (selective hydrogenations and preferential CO oxidation) all benefit from metal-metal and/or metal-oxide synergies. As these reactions involve hydrogen-rich environments, hydrogen absorption in the metal lattice can have a drastic influence on the catalytic properties.5,6 Moreover, advanced microscopy and spectroscopy techniques reveal additional major effects of the gaseous atmosphere and the support on the catalyst phase, such as changes in nanoparticle morphology, chemical arrangement and oxidation state (Fig. 1).4,7 Finally, as will be shown from operando techniques in the prototypical case of CO oxidation over Pt/-Al2O3, the influence of the thermochemical environment is even more dramatic for the stability of recently emerging “singe-atom catalysts”.8,9 Confronting experimental observations with computer simulations enables us to identify the key structural drivers and elucidate the reaction mechanisms.2,7,9,10(1) Piccolo, L. Surface Studies of Catalysis by Metals: Nanosize and Alloying Effects. In Nanoalloys: Synthesis, Structure and Properties; Alloyeau, D., Mottet, C., Ricolleau, C., Eds.; Engineering Materials; Springer London, 2012; pp 369–404.(2) Piccolo, L.; Chatelier, C.; Weerd, M.-C. D.; Morfin, F.; Ledieu, J.; Fournée, V.; Gille, P.; Gaudry, E. Sci. Technol. Adv. Mater. 2019, 20, 557–567.(3) Nguyen, T.-S.; Laurenti, D.; Afanasiev, P.; Konuspayeva, Z.; Piccolo, L. J. Catal. 2016, 344, 136–140.(4) Morfin, F.; Nguyen, T.-S.; Rousset, J.-L.; Piccolo, L. Appl. Catal. B 2016, 197, 2–13.(5) Zlotea, C.; Morfin, F.; Nguyen, T.-S.; Nguyen, N.-T.; Nelayah, J.; Ricolleau, C.; Latroche, M.; Piccolo, L. Nanoscale 2014, 6, 9955–9959.(6) Zlotea, C.; Oumellal, Y.; Provost, K.; Morfin, F.; Piccolo, L. Appl. Catal. B 2018, 237, 1059–1065.(7) Piccolo, L.; Li, Z. Y.; Demiroglu, I.; Moyon, F.; Konuspayeva, Z.; Berhault, G.; Afanasiev, P.; Lefebvre, W.; Yuan, J.; Johnston, R. L. Sci. Rep. 2016, 6, 35226.(8) Dessal, C.; Len, T.; Morfin, F.; Rousset, J.-L.; Aouine, M.; Afanasiev, P.; Piccolo, L. ACS Catal. 2019, 9, 5752–5759.(9) Dessal, C.; Sangnier, A.; Chizallet, C.; Dujardin, C.; Morfin, F.; Rousset, J.-L.; Aouine, M.; Bugnet, M.; Afanasiev, P.; Piccolo, L. Nanoscale 2019, 11, 6897–6904.(10) Goyhenex, C.; Piccolo, L. Phys. Chem. Chem. Phys. 2017, 19, 32451–32458
Nanocatalysis for energy applications
No full textSSCI-VIDE+ECI2D+LPIInternational audienceHeterogeneous catalysis, which is currently used in most industrial chemical processes, has an even stronger role to play in the energy transition, owing to its intrinsic ability to decrease the activation energy of thermodynamically feasible reactions.1 Present and future applications of catalysis for energy -including photo- and electrocatalysis- comprise petroleum refining, fuel cells, batteries, hydrogen production and storage, and biomass conversion.2 Heterogeneous catalysts often consist of transition metal nanoparticles and, more recently, single atoms supported on high-surface-area solids. This presentation will illustrate several fundamental aspects of nanocatalysis for energy-related reactions such as preferential oxidation of CO,3–5 methane reforming,6 and hydrodeoxygenation of biosourced compounds.7 It will be shown that the careful design of nanocatalysts, through the choice of suitable metals and supports, and the tuning of nanoparticle size and composition,1 allow improving catalytic performances. These investigations benefit from the use of advanced microscopy and spectroscopy techniques as well as computational methods,8–10 revealing the interplay between catalyst structure, reaction medium, and catalytic properties. (1) Piccolo, L. Surface Studies of Catalysis by Metals: Nanosize and Alloying Effects. In Nanoalloys: Synthesis, Structure and Properties; Alloyeau, D., Mottet, C., Ricolleau, C., Eds.; Engineering Materials; Springer London, 2012; pp 369–404.(2) New and Future Developments in Catalysis, S.L. Suib.; Elsevier: Amsterdam, 2013.(3) Zlotea, C.; Morfin, F.; Nguyen, T.-S.; Nguyen, N.-T.; Nelayah, J.; Ricolleau, C.; Latroche, M.; Piccolo, L. Nanoscale 2014, 6, 9955–9959.(4) Morfin, F.; Nguyen, T.-S.; Rousset, J.-L.; Piccolo, L. Appl. Catal. B 2016, 197, 2–13.(5) Zlotea, C.; Oumellal, Y.; Provost, K.; Morfin, F.; Piccolo, L. Appl. Catal. B 2018, 237, 1059–1065.(6) Nguyen, T. S.; Postole, G.; Loridant, S.; Bosselet, F.; Burel, L.; Aouine, M.; Massin, L.; Morfin, F.; Gélin, P.; Piccolo, L. J. Mater. Chem. A 2014, 2, 19822–19832.(7) Nguyen, T.-S.; Laurenti, D.; Afanasiev, P.; Konuspayeva, Z.; Piccolo, L. J. Catal. 2016, 344, 136–140.(8) Piccolo, L.; Li, Z. Y.; Demiroglu, I.; Moyon, F.; Konuspayeva, Z.; Berhault, G.; Afanasiev, P.; Lefebvre, W.; Yuan, J.; Johnston, R. L. Sci. Rep. 2016, 6, 35226.(9) Roiban, L.; Koneti, S.; Morfin, F.; Nguyen, T.-S.; Mascunan, P.; Aouine, M.; Epicier, T.; Piccolo, L. ChemCatChem 2017, 9, 4607–4613.(10) Goyhenex, C.; Piccolo, L. Phys. Chem. Chem. Phys. 2017, 19, 32451–32458
Nanocatalysis for energy applications
No full textSSCI-VIDE+ECI2D+LPIInternational audienceHeterogeneous catalysis, which is currently used in most industrial chemical processes, has an even stronger role to play in the energy transition, owing to its intrinsic ability to decrease the activation energy of thermodynamically feasible reactions.1 Present and future applications of catalysis for energy -including photo- and electrocatalysis- comprise petroleum refining, fuel cells, batteries, hydrogen production and storage, and biomass conversion.2 Heterogeneous catalysts often consist of transition metal nanoparticles and, more recently, single atoms supported on high-surface-area solids. This presentation will illustrate several fundamental aspects of nanocatalysis for energy-related reactions such as preferential oxidation of CO,3–5 methane reforming,6 and hydrodeoxygenation of biosourced compounds.7 It will be shown that the careful design of nanocatalysts, through the choice of suitable metals and supports, and the tuning of nanoparticle size and composition,1 allow improving catalytic performances. These investigations benefit from the use of advanced microscopy and spectroscopy techniques as well as computational methods,8–10 revealing the interplay between catalyst structure, reaction medium, and catalytic properties. (1) Piccolo, L. Surface Studies of Catalysis by Metals: Nanosize and Alloying Effects. In Nanoalloys: Synthesis, Structure and Properties; Alloyeau, D., Mottet, C., Ricolleau, C., Eds.; Engineering Materials; Springer London, 2012; pp 369–404.(2) New and Future Developments in Catalysis, S.L. Suib.; Elsevier: Amsterdam, 2013.(3) Zlotea, C.; Morfin, F.; Nguyen, T.-S.; Nguyen, N.-T.; Nelayah, J.; Ricolleau, C.; Latroche, M.; Piccolo, L. Nanoscale 2014, 6, 9955–9959.(4) Morfin, F.; Nguyen, T.-S.; Rousset, J.-L.; Piccolo, L. Appl. Catal. B 2016, 197, 2–13.(5) Zlotea, C.; Oumellal, Y.; Provost, K.; Morfin, F.; Piccolo, L. Appl. Catal. B 2018, 237, 1059–1065.(6) Nguyen, T. S.; Postole, G.; Loridant, S.; Bosselet, F.; Burel, L.; Aouine, M.; Massin, L.; Morfin, F.; Gélin, P.; Piccolo, L. J. Mater. Chem. A 2014, 2, 19822–19832.(7) Nguyen, T.-S.; Laurenti, D.; Afanasiev, P.; Konuspayeva, Z.; Piccolo, L. J. Catal. 2016, 344, 136–140.(8) Piccolo, L.; Li, Z. Y.; Demiroglu, I.; Moyon, F.; Konuspayeva, Z.; Berhault, G.; Afanasiev, P.; Lefebvre, W.; Yuan, J.; Johnston, R. L. Sci. Rep. 2016, 6, 35226.(9) Roiban, L.; Koneti, S.; Morfin, F.; Nguyen, T.-S.; Mascunan, P.; Aouine, M.; Epicier, T.; Piccolo, L. ChemCatChem 2017, 9, 4607–4613.(10) Goyhenex, C.; Piccolo, L. Phys. Chem. Chem. Phys. 2017, 19, 32451–32458
Reaction-induced changes in structure and activity of supported platinum catalysts investigated in situ: from single atoms to clusters
No full textSSCI-VIDE+CATREN+LPINational audienceStimulated by recent advances in scanning transmission electron microscopy (STEM), single-atom catalysts (SACs) have become prominent materials in heterogeneous catalysis.[1] In spite of the numerous reports on promising catalytic performance and noble-metal saving, single-atom stabilization remains a challenge – in particular for noble metals on oxides.[2] In addition, single atoms are not necessarily more efficient than their cluster or nanoparticle counterparts.[3] In this presentation, the previous issues will be illustrated for two prototypical catalytic systems: CO oxidation on Pt/Al2O3 and photocatalytic hydrogen evolution reaction over Pt/TiO2. The combined use of catalytic testing, STEM, operando X-ray and infrared absorption spectroscopies, and DFT calculations, reveal the influence of the reactive environment on Pt nuclearity and oxidation state (generally consisting in clustering and reduction, which in turn correlate to changes in catalytic activity.[4–7] From this knowledge, strategies can be suggested to stabilize the metals in an ultradispersed state.References: 1. Lang, R.; Du, X.; Huang, Y.; Jiang, X.; Zhang, Q.; Guo, Y.; Liu, K.; Qiao, B.; Wang, A.; Zhang, T. Chem. Rev. 2020, 120 (21), 11986–12043. 2. Piccolo, L. Catal. Today in press, doi: 10.1016/j.cattod.2020.03.052. 3. Beniya, A.; Higashi, S. Nat. Catal. 2019, 2 (7), 590–602. 4. Dessal, C.; Sangnier, A.; Chizallet, C.; Dujardin, C.; Morfin, F.; Rousset, J.-L.; Aouine, M.; Bugnet, M.; Afanasiev, P.; Piccolo, L. Nanoscale 2019, 11 (14), 6897–6904. 5. Dessal, C.; Len, T.; Morfin, F.; Rousset, J.-L.; Aouine, M.; Afanasiev, P.; Piccolo, L. ACS Catal. 2019, 9 (6), 5752–5759. 6. Dessal, C.; Martínez, L.; Maheu, C.; Len, T.; Morfin, F.; Rousset, J.-L.; Puzenat, E.; Afanasiev, P.; Aouine, M.; Soler, L.; Llorca, J.; Piccolo, L. J. Catal. 2019, 375, 155–163. 7. Piccolo, L.; Afanasiev, P.; Morfin, F.; Len, T.; Dessal, C.; Rousset, J. L.; Aouine, M.; Bourgain, F.; Aguilar-Tapia, A.; Proux, O.; Chen, Y.; Soler, L.; Llorca, J. ACS Catal. 2020, 10 (21), 12696–12705
Reaction-induced changes in structure and activity of supported platinum catalysts investigated in situ: from single atoms to clusters
No full textSSCI-VIDE+CATREN+LPINational audienceStimulated by recent advances in scanning transmission electron microscopy (STEM), single-atom catalysts (SACs) have become prominent materials in heterogeneous catalysis.[1] In spite of the numerous reports on promising catalytic performance and noble-metal saving, single-atom stabilization remains a challenge – in particular for noble metals on oxides.[2] In addition, single atoms are not necessarily more efficient than their cluster or nanoparticle counterparts.[3] In this presentation, the previous issues will be illustrated for two prototypical catalytic systems: CO oxidation on Pt/Al2O3 and photocatalytic hydrogen evolution reaction over Pt/TiO2. The combined use of catalytic testing, STEM, operando X-ray and infrared absorption spectroscopies, and DFT calculations, reveal the influence of the reactive environment on Pt nuclearity and oxidation state (generally consisting in clustering and reduction, which in turn correlate to changes in catalytic activity.[4–7] From this knowledge, strategies can be suggested to stabilize the metals in an ultradispersed state.References: 1. Lang, R.; Du, X.; Huang, Y.; Jiang, X.; Zhang, Q.; Guo, Y.; Liu, K.; Qiao, B.; Wang, A.; Zhang, T. Chem. Rev. 2020, 120 (21), 11986–12043. 2. Piccolo, L. Catal. Today in press, doi: 10.1016/j.cattod.2020.03.052. 3. Beniya, A.; Higashi, S. Nat. Catal. 2019, 2 (7), 590–602. 4. Dessal, C.; Sangnier, A.; Chizallet, C.; Dujardin, C.; Morfin, F.; Rousset, J.-L.; Aouine, M.; Bugnet, M.; Afanasiev, P.; Piccolo, L. Nanoscale 2019, 11 (14), 6897–6904. 5. Dessal, C.; Len, T.; Morfin, F.; Rousset, J.-L.; Aouine, M.; Afanasiev, P.; Piccolo, L. ACS Catal. 2019, 9 (6), 5752–5759. 6. Dessal, C.; Martínez, L.; Maheu, C.; Len, T.; Morfin, F.; Rousset, J.-L.; Puzenat, E.; Afanasiev, P.; Aouine, M.; Soler, L.; Llorca, J.; Piccolo, L. J. Catal. 2019, 375, 155–163. 7. Piccolo, L.; Afanasiev, P.; Morfin, F.; Len, T.; Dessal, C.; Rousset, J. L.; Aouine, M.; Bourgain, F.; Aguilar-Tapia, A.; Proux, O.; Chen, Y.; Soler, L.; Llorca, J. ACS Catal. 2020, 10 (21), 12696–12705
First measurements on a discrete-time front-end in 28-nm CMOS technology for timing pixel detectors
No full textThis work presents the first results on a CMOS analog front-end in 28 nm commercial technology. The proposed scheme was designed to be compatible with future 4D vertex detector requirements for high energy physics experiments, such as: high granularity with a pixel pitch smaller than 100 μm, an average event-rate per unit area of 3 GHzcm-2 [5] and a radiation dose up to 1014 MeV neqcm2. In order to fulfill these system requirements the front-end needs to integrate time measurement capabilities at the pixel level with a resolution better than 100 ps and a power consumption of the order of 10 μW per channel. Analog solutions has been adopted to minimize the effect of per-channel mismatch and process variation on the timing measure with minimal external control. A front-end with an auto zeroed comparator was chosen for this purpose due to its ease of control and low power consumption. A first prototype ASIC has been manufactured and is now under test. In this paper first measurements on its timing performance and offset-compensation capabilities are presented
Assessment of nonverbal communication in clinical encounters: many methodological approaches, but no gold standard
No full texteditoria
Simon O. Fiks
No full textAttività del pittore Simon O. Fiks in Italia nella prima metà del Novecent
From research to clinical practice: a systematic review of the implementation of psychological interventions for chronic headache in adults
Full text linkBackground: Psychological interventions have been proved to be effective in chronic headache (CH) in adults. Nevertheless, no data exist about their actual implementation into standard clinical settings. We aimed at critically depicting the current application of psychological interventions for CH into standard care exploring barriers and facilitators to their implementation. Secondarily, main outcomes of the most recent psychological interventions for CH in adults have been summarized. Methods: We conducted a systematic review through PubMed and PsycINFO in the time range 2008-2018. A quality analysis according to the QATSDD tool and a narrative synthesis were performed. We integrated results by: contacting the corresponding author of each paper; exploring the website of the clinical centers cited in the papers. Results: Of the 938 identified studies, 28 papers were selected, whose quality largely varied with an average %QATSDD quality score of 64.88%. Interventions included CBT (42.85%), multi-disciplinary treatments (22.43%), relaxation training (17.86%), biofeedback (7.14%), or other interventions (10.72%). Treatments duration (1 day-9 months) and intensity varied, with a prevalence of individual-basis implementation. The majority of the studies focused on all primary headaches; 4 studies focused on medication-overuse headache. Most of the studies suggest interventions as effective, with the reduction in frequency of attacks as the most reported outcome (46.43%). Studies were distributed in different countries, with a prevalent and balanced distribution in USA and Europe. Ten researches (35.71%) were performed in academic contexts, 11 (39.28%) in clinical settings, 7 (25%) in pain/headache centres. Interventions providers were professionals with certified experience. Most of the studies were funded with private or public funding. Two contacted authors answered to our e-mail survey, with only one intervention implemented in the routine clinical practice. Only in three out of the 16 available websites a reference to the implementation into the clinical setting was reported. Conclusion: Analysis of contextual barriers/facilitators and cost-effectiveness should be included in future studies, and contents regarding dissemination/implementation of interventions should be incorporated in the professional training of clinical scientists. This can help in filling the gap between the existing published research and treatments actually offered to people with CH
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