Publications by authors named "Raquel Aymerich Armengol"

Niobium oxide (NbO) is a versatile semiconductor material with photochromic properties. This study investigates the local structure of noncrystalline, short-range-ordered niobium oxide synthesized via a sol-gel method. X-ray atomic pair distribution function analysis unravels the structural arrangements within the noncrystalline materials at a local scale.

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Identical location (scanning) transmission electron microscopy provides valuable insights into the mechanisms of the activity and degradation of nanocatalysts during electrochemical reactions. However, the technique suffers from limitations that hinder its widespread use for nanocatalysts of gas evolving reactions, e.g.

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Rhodium-platinum core-shell nanoparticles on a carbon support (Rh@Pt/C NPs) are promising candidates as anode catalysts for polymer electrolyte membrane fuel cells. However, their electrochemical stability needs to be further explored for successful application in commercial fuel cells. Here we employ identical location scanning transmission electron microscopy to track the morphological and compositional changes of Rh@Pt/C NPs during potential cycling (10 000 cycles, 0.

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Supported metal catalysts with partial encapsulation resulting from strong metal-support interactions show distinctive structural features which strongly affect their functionalities. Yet, challenges in systematic synthesis and in-depth characterization for such systems limit the present understanding of structure-property relationships. Herein, the synthesis and characterization of two Pt/TiO models are conducted by a simple change of the synthesis order, while keeping all other parameters constant.

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The incorporation of impurities during the chemical synthesis of nanomaterials is usually uncontrolled and rarely reported because of the formidable challenge in measuring trace amounts of often light elements with sub-nanometer spatial resolution. And yet, these foreign elements (introduced by doping, for example) influence functional properties. We demonstrate how the hydrothermal growth and a partial reduction reaction on hollow TiO nanowires leads to the introduction of parts per millions of boron, sodium, and nitrogen.

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