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The growth of ZnO clusters supported by ZnO‐bilayers on Ag(111) and the interaction of these oxide nanostructures with water have been studied by a multi‐technique approach combining temperature‐dependent infrared reflection absorption spectroscopy (IRRAS), grazing‐emission X‐ray photoelectron spectroscopy, and density functional theory calculations. Our results reveal that the ZnO bilayers exhibiting graphite‐like structure are chemically inactive for water dissociation, whereas small ZnO clusters formed on top of these well‐defined, yet chemically passive supports show extremely high reactivity ‐ water is dissociated without an apparent activation barrier. Systematic isotopic substitution experiments using H2 16O/D2 16O/D2 18O allow identification of various types of acidic hydroxyl groups. We demonstrate that a reliable characterization of these OH‐species is possible via co‐adsorption of CO, which leads to a red shift of the OD frequency due to the weak interaction via hydrogen bonding. The theoretical results provide atomic‐level insight into the surface structure and chemical activity of the supported ZnO clusters and allow identification of the presence of under‐coordinated Zn and O atoms at the edges and corners of the ZnO clusters as the active sites for H2O dissociation., Chemical nature of small ZnO clusters: The combined infrared reflection absorption spectroscopy (IRRAS) and theoretical results reveal that the Ag(111)‐supported graphitic ZnO bilayers are chemically inactive. Significant activity is observed when small ZnO clusters are supported by these bilayers. This apparently barrier‐free water dissociation takes place at under‐coordinated Zn and O atoms at the edges and corners of the ZnO nanostructures. Various acidic hydroxyl species are identified by isotopic substitution experiments and the formation of weak H bonds to coadsorbed CO molecules.

The applications of the most promising Fe-N-C catalysts are prohibited by their limited intrinsic activities. Manipulating the Fe energy level through anchoring electron-withdrawing ligands is found effective in boosting the catalytic performance. However, such regulation remains elusive as the ligands are only uncontrollably introduced oweing to their energetically unstable nature. Herein, we report a rational manipulation strategy for introducing axial bonded O to the Fe sites, attained through hexa-coordinating Fe with oxygen functional groups in the precursor. Moreover, the O modifier is stabilized by forming the Fe-O-Fe bridge bond, with the approximation of two FeN4 sites. The energy level modulation thus created confers the sites with an intrinsic activity that is over 10 times higher than that of the normal FeN4 site. Our finding opens a novel strategy to manage coordination environments at an atomic level for high activity ORR catalysts.

An atomic-level understanding of dioxygen activation on metal oxides remains one of the major challenges in heterogeneous catalysis. By performing a thorough surface-science study of all three low-index single-crystal surfaces of ceria, probably the most important redox catalysts, we provide a direct spectroscopic characterization of reactive dioxygen species at defect sites on the reduced ceria (110) and (100) surfaces. Surprisingly, neither of these superoxo and peroxo species was found on ceria (111), the thermodynamically most stable surface of this oxide. Applying density functional theory, we could relate these apparently inconsistent findings to a sub-surface diffusion of O-vacancies on (111) substrates, but not on the less closely packed surfaces. These observations resolve a long standing debate concerning the location of O-vacancies on ceria surfaces and the activation of O2 on ceria powders.

The surface atomic arrangement of metal oxides determines their physical and chemical properties, and the ability to control and optimize structural parameters is of crucial importance for many applications, in particular in heterogeneous catalysis and photocatalysis. Whereas the structures of macroscopic single crystals can be determined with established methods, for nanoparticles (NPs), this is a challenging task. Herein, we describe the use of CO as a probe molecule to determine the structure of the surfaces exposed by rod-shaped ceria NPs. After calibrating the CO stretching frequencies using results obtained for different ceria single-crystal surfaces, we found that the rod-shaped NPs actually restructure and expose {111} nanofacets. This finding has important consequences for understanding the controversial surface chemistry of these catalytically highly active ceria NPs and paves the way for the predictive, rational design of catalytic materials at the nanoscale.

The goal of this study was to provide a preliminary evaluation of a social skills and facilitated play early intervention programme to promote social interaction, prosocial behaviours and socio-communicative skills among young extremely shy children in China. Participants were a sample of n = 16 extremely shy young children attending kindergarten in Shanghai, China. Children were randomly assigned to either the Social Skills Facilitated Play or comparison condition. Baseline, post-intervention and 2-month follow-up measures included observations of children's social behaviours in quartets of novel peers. Result indicated that as compared with shy controls, shy children who participated in the Social Skills Training Facilitated Play programme were observed to demonstrate significantly greater post-intervention frequencies of peer interactions (e.g. group play and peer conversation) and prosocial behaviours (e.g. cooperation, sharing and making/accepting social initiations) during unstructured free play with novel peers, as well as better social-communicative competence during a speech task. Almost all of these improvements were maintained 2 months post-intervention. Results are discussed in terms of the importance of developing and refining early intervention programmes for extremely shy young children in China. Copyright © 2016 John Wiley & Sons, Ltd.

[DE] Das Konzept der “festen Lösungen mit gemischten Linkern” (mixed-linker solid solution concept) ist angewendet worden, um die Metallzentren des gemischtvalenten RuII/III-Analogons der bekannten Familie der [M3II,II(btc)2]-MOFs (M=Cu, Mo, Cr, Ni oder Zn; btc=Benzol-1,3,5-tricarboxylat) zu modellieren und strukturelle Defekte in das Gerüst mit teilweise fehlenden Carboxylatliganden an den Ru2-“Schaufelradeinheiten” einzubringen. Pyridin-3,5-dicarboxylat (pydc) als zweiter, Defekt-bildender Linker von ähnlicher Größe wie btc, aber geringerer Ladung führt zu einem porösen Derivat von Ru-MOF mit Eigenschaften, die sich von denen des Defekt-freien MOF unterscheiden. So bewirkt das Einbringen von pydc außer der Bildung von zusätzlichen koordinativ ungesättigten Metallzentren auch eine partielle Reduktion des Rutheniums. Die modifizierten Ru-Zentren sind für die Aktivität der “defekten” Varianten hinsichtlich dissoziativer Chemisorption von CO2, erhöhter CO-Sorption, Bildung von Ru-H-Spezies und katalytischer Hydrierung von Olefinen verantwortlich.

A mixed-linker solid-solution approach was employed to modify the metal sites and introduce structural defects into the mixed-valence Ru-II/III structural analogue of the well-known MOF family [M-3(II,II)(btc)(2)] (M= Cu, Mo, Cr, Ni, Zn; btc= benzene-1,3,5-tricarboxylate), with partly missing carboxylate ligators at the Ru-2 paddle-wheels. Incorporation of pyridine-3,5-dicarboxylate (pydc), which is the same size as btc but carries lower charge, as a second, defective linker has led to the mixed-linker isoreticular derivatives of Ru-MOF, which display characteristics unlike those of the defect-free framework. Along with the creation of additional coordinatively unsaturated sites, the incorporation of pydc induces the partial reduction of ruthenium. Accordingly, the modified Ru sites are responsible for the activity of the "defective" variants in the dissociative chemisorption of CO2, the enhanced performance in CO sorption, the formation of hydride species, and the catalytic hydrogenation of olefins., O.K. acknowledges Ruhr-University Research School (http://www.research-school.rub.de) for admission and additional support of her PhD project. I. L. and F. X. L. X. acknowledge support by Consolider-Ingenio 2010 (project MULTICAT) and the "Severo Ochoa" program.

$Au/TiO_{2}$-Katalysatoren, die durch das “Deposition-Precipitation”-Verfahren hergestellt und ohne Kalzinierung eingesetzt wurden, erreichten in der CO-Oxidation hohe, weitgehend temperaturunabhängige Umsätze. Dagegen erschien nach thermischen Vorbehandlungen, z. B. in He bei 623 K, die Umsatz-Temperatur-Charakteristik in der bekannten S-Form, mit Aktivierungsenergien nahe $30 kJ mol^{−1}$. Charakterisierung der Proben durch XAFS und HAADF-STEM sowie eine Tieftemperatur-IR-Studie von Adsorption und Oxidation des CO zeigten, dass letzteres am frisch präparierten (gefriergetrockneten) Katalysator, der Gold ausschließlich als $Au^{3+}$ enthielt, bereits bei 90 K durch Gasphasensauerstoff oxidiert wurde. Nach Aktivierung im Reaktantenstrom geht der CO-Umsatz bei niedrigen Reaktionstemperaturen auf Zentren zurück, die $Au^{III}$ enthalten, bei höheren Temperaturen wird er von $Au^{0}$ getragen. Nach thermischen Behandlungen wird CO im ganzen Temperaturbereich an Zentren umgesetzt, die ausschließlich metallisches Gold enthalten.

Surface-modified TiO2 photocatalysts were synthesized by a photosynthetic route involving visible-light-induced (λ>455 nm) activation of benzene and toluene at the surface of TiO2 leading to the formation of carbonaceous polymeric deposits. IR spectroscopic and photoelectrochemical experiments showed that the mechanism of the photosynthetic reactions involves intra-bandgap surface states at TiO2 related to surface OH groups interacting with adsorbed aromatic molecules. The photosynthesized surface-modified TiO2 materials exhibited enhanced activity, relative to pristine TiO2 , in photocatalytic degradation (and complete mineralization) of 4-chlorophenol. The improvement was pronounced particularly under visible-light (λ>455 nm) irradiation with the relative initial photodegradation rate enhanced by a factor of four. The surface-modified photocatalysts exhibited good stability under the operating conditions, and the optimum carbon content was approximately 0.5 wt %. Mechanistic studies showed that the enhanced visible-light photodegradation of 4-chlorophenol is due to modified surface-adsorption properties that facilitate formation of a surface complex between titania and 4-chlorophenol, rather than due to any sensitizing effect of the carbonaceous deposits. The study highlights the importance of considering the interaction between pollutant molecules and the photocatalyst surface in heterogeneous photocatalysis, and possibly opens up a route for photosynthesis of further surface-modified photocatalysts with tuned surface properties.

Crystals of MIL-88B-Fe and NH2-MIL-88B-Fe were prepared by a new rapid microwave-assisted solvothermal method. High-purity, spindle-shaped crystals of MIL-88B-Fe with a length of about 2 μm and a diameter of 1 μm and needle-shaped crystals of NH2-MIL-88B-Fe with a length of about 1.5 μm and a diameter of 300 nm were produced with uniform size and excellent crystallinity. The possibility to reduce the as-prepared frameworks and the chemical capture of carbon monoxide in these materials was studied by in situ ultrahigh vacuum Fourier-transform infrared (UHV-FTIR) spectroscopy and Mössbauer spectroscopy. CO binding occurs to unsaturated coordination sites (CUS). The release of CO from the as-prepared materials was studied by a myoglobin assay in physiological buffer. The release of CO from crystals of MIL-88B-Fe with t(1/2) = 38 min and from crystals of NH2-MIL-88B-Fe with t(1/2) = 76 min were found to be controlled by the degradation of the MIL materials under physiological conditions. These MIL-88B-Fe and NH2-MIL-88B-Fe materials show good biocompatibility and have the potential to be used in pharmacological and therapeutic applications as carriers and delivery vehicles for the gasotransmitter carbon monoxide.

Metal oxides and metal nanoparticles dispersed on oxide substrates have gained increasing interest in surface science because of their widespread applications, especially in heterogeneous catalysis. In this review we summarize our recent vibrational spectroscopic studies on pure and metal-covered oxide surfaces (ZnO, TiO2, Au/ZnO and Cu/ZnO) using a number of small molecules (H2, CO, CO2, NO and HCOOH) as probes and/or reactants. High-resolution electron energy loss spectroscopy (HREELS) turned out to be a powerful tool to investigate well-defined oxide and metal/oxide model systems. The application of a novel ultrahigh vacuum IR spectroscopy (UHV-FTIRS) apparatus allowed us to record high-quality IR data on oxide surfaces of both single crystals and polycrystalline powder particles. We will particularly focus on following important issues: (i) the interaction of hydrogen with ZnO; (ii) structure and reactivity of polar and nonpolar ZnO surfaces; (iii) the role of defects in surface chemistry of oxides; (iv) the origin of significant difference in photocatalytic activity between anatase and rutile TiO2 and (v) the interaction between metal nanoparticles and oxide supports. We will demonstrate that the data from HREELS and UHV-FTIRS provide detailed insight into structural, electronic and chemical properties of the studied systems.

Deprotonating a base: High surface coverage is found to be capable of inducing proton transfer from adsorbed ammonia to surface oxygen atoms on ZnO of both single crystals and nanoparticles by means of HREELS and UHV-FTIRS vibrational spectroscopies and confirmed by density functional theory calculations

Die Rolle von Defekten, besonders von Sauerstoff-Fehlstellen, auf Oxidoberfl chen gilt seit je als entscheidend in der Grenzfl chenchemie derartiger Substrate. In j ngster Zeit sind auf diesem Gebiet vor allem bei Titandioxid (TiO2) erhebliche Fortschritte durch die Kombination von Rastertunnelmikroskopie (STM) und Rechnungen mit Dichtefunktionaltheorie (DFT) erzielt worden. So konnten etwa die H2ODissoziation, die O2-Dissoziation [2–4] und (De-)Hydrierungsreaktionen von aromatischen Verbindungen sehr ausf hrlich untersucht werden. Leider kann das experimentelle Verfahren, dem diese Fortschritte im wesentlichen zu verdanken sind, n mlich die Rastertunnelmikroskopie (STM), auf Pulver, die technisch wichtigste Form von Oxidmaterialien, nicht angewendet werden. Auch wenn ber einige (wenige) STM-Untersuchungen an Pulverteilchen von Nanometergrcse berichtet worden ist, kcnnen chemische Reaktionen an Oxidoberfl chen und die Rolle von Sauerstoff-Fehlstellen an Oberfl chen von Nanopartikeln nicht ohne weiteres untersucht werden. Eine andere experimentelle Technik, die Infrarot(IR)Spektroskopie ist schon in grosem Umfang f r die Untersuchung chemischer Prozesse an Oxidpulvern eingesetzt worden. Allerdings gibt es nur sehr wenig Resultate an wohldefinierten, einkristallinen Oxidoberfl chen. Infolgedessen ist der oberfl chenwissenschaftliche Ansatz, der bei der Aufkl rung der Reaktionsmechanismen an Metallpartikeln durch Vergleich mit Ergebnissen f r wohldefinierte Einkristall-Bezugssysteme mit grosem Erfolg eingesetzt worden ist, bei der Aufkl rung von Reaktionen auf Oxidoberfl chenmit grosen Schwierigkeiten behaftet. Hier stellen wir einen neuen Ansatz vor, mit dem Sauerstoff-Fehlstellen sowohl auf Oberfl chen aus Oxid-Einkristallen wie auch auf Pulverteilchen untersucht werden kcnnen. Wir verwenden dieses Verfahren, um nachzuweisen, dass die Oberfl chenchemie von Formaldehyd auf TiO2-Nanopartikeln tats chlich von der Dichte der O-Fehlstellen bestimmt wird. Wir werden zun chst zeigen, dass das Vorliegen von Sauerstoff-Fehlstellen auf Oberfl chen von Rutil-TiO2 (r-TiO2) mit Ultrahochvakuum-IR-Spektroskopie (UHV-FTIRS) unter Verwendung von CO als Sondenmolek l direkt bestimmt werden kann. Nach Kalibrierung dieses Verfahrens mit einem gut definierten, r-TiO2(110)-Einkristallsubstrat werden wir es bei den entsprechenden Pulverproben anwenden. Die Reflexions-Absorptions-IR-Spektroskopie (RAIRS)Daten in Abbildung 1 zeigen, dass auf einer vollst ndig oxidierten r-TiO2(110)-Oberfl che mit geringer Fehlstellendichte nur eine einzige Bande bei 2188 cm 1 im CO-Streck

ZrO2/SiO2 nanocomposites with Zr loadings in the range 0.88 wt % to 12.2 wt % were prepared by a two-step metal-organic (MO)CVD process in a fluidized-bed reactor with the Zr alkoxide [Zr(OiPr)2(tbaoac)2] as the precursor. The high surface area of silica was hardly diminished by the deposition, and the deposited zirconia species were highly dispersed, as indicated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) investigations. The XPS data reveal a linear increase of the Zr surface concentration with increasing Zr loading. The high degree of dispersion is attributed to a strong interaction between the zirconia species and the support through the formation of Si-O-Zr bonds. Correspondingly, the intensity of the isolated silanol bands detected by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) was found to decrease with increasing Zr loading.