Morphology and Gas Adsorption Properties of Palladium−Cobalt-Based Cyanogels

Abstract

The morphology of cyanide-bridged palladium−cobalt (Pd−Co) gels, synthesized from aqueous solutions of Na2PdCl4 and K3[Co(CN)6], is elucidated using nitrogen and carbon dioxide adsorption, permeability measurements, electron microscopy, and small-angle X-ray scattering. The aerogels formed from the Pd−Co hydrogels possess both micro- and mesoporosity. Electron microscopy indicates that the aerogels are constituted of spherical microporous particles; the interstices between these particles constitute the mesopores. The aerogel surfaces are found to be fractal as analyzed by gas adsorption and small-angle X-ray scattering. Both these techniques yield, within experimental error, the same surface fractal dimension of 2.6 ± 0.2 for the aerogels. The Pd−Co xerogels, unlike the aerogels, are predominantly microporous with a narrow microporosity. Transmission electron microscopy reveals that the xerogels are constituted of particles of an average size of ∼10 nm. Unlike the aerogels, the xerogels do not possess surface fractality. The mechanism of adsorption of different gases on these gels is analyzed on the basis of the gel morphologies.

Catalytic ammonolytic sol–gel preparation of a mesoporous silicon aluminium nitride from a single-source precursor

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Large-scale synthesis of organometallic polymer flowers with ultrathin petals for hydrogen peroxide sensing

“…[1][2][3][4][5][6][7] Controlling morphologies of the nanomaterials has been proven to be a promising approach for optimizing their properties and exploring new functionalities. [1][2][3][4][5][6][7] Controlling morphologies of the nanomaterials has been proven to be a promising approach for optimizing their properties and exploring new functionalities.…”

Preparation, Structural Characterization, and Thermal Ammonolysis of Two Novel Dimeric Transition Silylamide Complexes

“…The synthetic flexibility and low reaction temperatures of sol–gel techniques render this technique an attractive approach for preparing micro/mesoporous oxide materials as powders, membranes, and filters with high purity and homogeneity 3 . A number of highly porous, nonoxide ceramics prepared by sol–gel processes have also been reported, that is boron nitride, 4–8 metal (carbo)nitrides, 9–14 silicon carbonitride, 15–21 and boron carbonitride 22,23 . Polymeric boron‐, titano,‐ and tantalo‐silazanes have been prepared by a sol–gel process by controlled coammonolysis of elemental alkylamides 24 .…”