Nanostructured ZnO: From monodisperse nanoparticles to nanorods

Ge, Mingyuan; Wu, Hanglong; Niu, Ling; Liu, J.F.; Chen, S.Y.; Shen, Pouyan; Zeng, Yiyu; Wang, Y.W.; Zhang, G.Q.; Jiang, Jian

doi:10.1016/j.jcrysgro.2007.03.016

Cited by 71 publications

(48 citation statements)

References 39 publications

(26 reference statements)

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“…Overall it was concluded that the onset of PdZn alloy formation was not affected by the morphology of the ZnO support. Lattice fringes of 0.28 nm were measured from HRTEM micro-graphs for ZnO O2, ZnO H2 and ZnO COM which can be attributed to the exposure of a ZnO non-polar (1 0 0) plane [29] which is in agreement with the XRD findings. The formation of PdZn alloy under reduction atmosphere in all of the samples was also further supported by the lattice spacing measurements from HRTEM micrographs.…”

Section: Physicochemical Characterization Of Pdzn/zno Catalystssupporting

confidence: 84%

Ultraselective low temperature steam reforming of methanol over PdZn/ZnO catalysts—Influence of induced support defects on catalytic performance

Eblagon

Concepción

Silva

et al. 2014

Applied Catalysis B: Environmental

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The influence of the calcination atmosphere of ZnO precursor (Zn4(CO)3(OH)6·H2O) on the catalytic performance of a series of PdZn/ZnO catalysts was studied for production of H2 via low temperature (180 • C) direct methanol steam reforming (low temperature-MSR). The catalytic activity and selectivity of PdZn/ZnO were found to be strongly influenced by the calcination atmosphere of ZnO precursor and increased from oxidizing to reducing atmosphere, following the order (O2 < air < N2 < H2). As a result, a very active catalyst was obtained by simply supporting Pd on ZnO calcined in H2. Further evidence from XPS and TPR analysis indicated that calcination in reducing atmosphere gave rise to a significant increase in the concentration of oxygen vacancies on the surface of ZnO support. Thus, the superb performance of the best catalyst was attributed to the defect chemistry of ZnO support; mainly to the amount of oxygen vacancies present in the interface region, which act as additional active sites for water adsorption and subsequent activation. In addition, the formation of CO was drastically suppressed by replenishment of oxygen vacancies on ZnO support. Thus, it is clear that the abundance of specific active sites on PdZn/ZnO catalyst is strongly influenced by the preparation route of the ZnO support. Additionally, the PdZn alloy was discovered to be unstable under prolonged exposure to CO atmosphere and the stability test under methanol steam reforming conditions showed a 24% drop in conversion over 48 h testing period. This phenomena can have detrimental effect on the performance of this type of catalytic systems in continuous prolonged duty cycle time on-stream.

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Section: Physicochemical Characterization Of Pdzn/zno Catalystssupporting

confidence: 84%

Ultraselective low temperature steam reforming of methanol over PdZn/ZnO catalysts—Influence of induced support defects on catalytic performance

Eblagon

Concepción

Silva

et al. 2014

Applied Catalysis B: Environmental

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“…2bshows the SAED pattern of ZnO in silica in which six different rings are observed. The d-spacings of the rings are 0ZnO, respectively[10]. The ring-like SAED pattern of ZnO confirms the polycrystalline nature of ZnO nanocrystals in silica matrix.…”

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confidence: 54%

Effect of 750keV Argon ion irradiation on nc ZnOSiOx thin films

Kumar

2015

Applied Surface Science

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“…Cylindrical rod shaped particles with physical dimensions 500 nm length and 75 nm diameters can be evident in the 'CTAB-free' varistor nanopowders. Growth of nanorods have been extensively reported in simple reflux synthesis and arises from the charge imbalance between the positively charged reactive Zn-(0 0 0 1) surface and the negatively charged O-(0 0 0 1) inert surface [16,20]. The rod shaped varistor nanopowders will result in poor packing during compaction, making it difficult to obtain dense varistors at low temperatures.…”

Section: Characterization Of Nanocrystalline Varistor Powdermentioning

confidence: 99%