Pd@CeO2 core‐shell structures deposited onto a modified hydrophobic alumina (obtained by reacting alumina with triethoxy(octyl)silane) exhibit exceptionally high activity for methane oxidation, with complete conversion below 400 °C and outstanding thermal stability up to 850 °C.

Iron‐silica self‐organized membranes, so‐called chemical gardens, behave as fuel cells and catalyze the formation of amino/carboxylic acids and RNA nucleobases from organics that were available on early Earth. Despite their relevance for prebiotic chemistry, little is known about their structure and mineralogy at the nanoscale. Studied here are focused ion beam milled sections of iron‐silica membranes, grown from synthetic and natural, alkaline, serpentinization‐derived fluids thought to be widespread on early Earth. Electron microscopy shows they comprise amorphous silica and iron nanoparticles of large surface areas and inter/intraparticle porosities. Their construction resembles that of a heterogeneous catalyst, but they can also exhibit a bilayer structure. Surface‐area measurements suggest that membranes grown from natural waters have even higher catalytic potential. Considering their geochemically plausible precipitation in the early hydrothermal systems where abiotic organics were produced, iron‐silica membranes might have assisted the generation and organization of the first biologically relevant organics.

Iron-silica self-organized membranes,s o-called chemical gardens, behave as fuel cells and catalyze the formation of amino/carboxylic acids and RNAn ucleobases from organics that were available on early Earth. Despite their relevance for prebiotic chemistry,l ittle is knowna bout their structure and mineralogy at the nanoscale.S tudied here are focused ion beam milled sections of iron-silica membranes, grown from synthetic and natural, alkaline,s erpentinizationderived fluids thought to be widespread on early Earth. Electron microscopys hows they comprise amorphous silica and iron nanoparticles of large surface areas and inter/ intraparticle porosities.T heir construction resembles that of ah eterogeneous catalyst, but they can also exhibit ab ilayer structure.Surface-area measurements suggest that membranes grown from natural waters have even higher catalytic potential. Considering their geochemically plausible precipitation in the early hydrothermal systems where abiotic organics were produced, iron-silica membranes might have assisted the generation and organization of the first biologically relevant organics.

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The "Gold Dust Defect" affects the surface quality of AISI 430 ferritic stainless steels. However, there is a very limited number of studies focusing on it. To better understand its nature, we have combined several techniques, such as x-ray photoelectron spectroscopy, atomic force microscopy, and transmission electron microscopy, in order to extract a maximum of structural and compositional information. Our results show that the surface quality, microstructure, and chemistry of the samples are strongly affected by the aluminum content, the severity of the defect being the highest at the lowest Al concentration. Not only is the concentration of the defects at the surface strongly reduced when increasing the Al. at.% but the depth of the cavities is also reduced by a factor of 3 when the Al content is increased from 0.09  at.% to 0.59 at.%. Our results provide new information on the nature of this defect, and show that an increase of the aluminum content allows the Cr concentration to be maintained in the range of values required to maintain the passivity of the steel, thus improving the surface quality.