CeO₂/Pt Catalyst Nanoparticle Containing Carbide-Derived Carbon Composites by a New In situ Functionalization Strategy

Abstract

A new class of CeO 2 /Pt nanostructures containing highly porous carbide-derived carbon composites was obtained for the first time using a polymer precursor strategy and subsequent ceramization. The catalytic transition metal compounds were incorporated into polymeric polycarbosilane structures using an inverse microemulsion method in precisely tunable nanoscale particle sizes. Porous ceramic and carbon composites were obtained by pyrolysis and subsequent chlorination processes. The adsorption properties of nonoxidic ceramic intermediates can be adjusted by the pyrolysis temperatures from mainly microporous to meso-and macroporous materials, respectively. These pore structures remain during the chlorination process confirmed by comparative nitrogen physisorption and small-angle X-ray scattering investigations. The specific surface areas significantly increase up to 1774 m 2 /g after selective silicon removal. In comparison to unsupported CeO 2 /Pt nanoparticle structures, the particle sizes and dispersion of the active metal compounds of composite structures remain during pyrolysis and chlorination process studied by electron microscopy methods. Ceramic and carbonaceous composites show catalytic activity and stability in selective methane oxidation. In contrast to the SiC composites, the CDC materials promote the formation of carbon monoxide and hydrogen in reforming reactions at higher temperatures, a conversion pathway important for the generation of synthetic fuels.

Unravelling the Formation of Pt–Ga Alloyed Nanoparticles on Calcined Ga-Modified Hydrotalcites by in Situ XAS

“…The rational design of functional materials, such as heterogeneous catalysts, aims at manipulating the material’s structure by steering the solid-phase chemistry in order to achieve the desired properties and improve a material’s performance. − An in-depth understanding of materials chemistry is therefore crucial for the development of better catalysts and enabling the chemical industry to shift from nonselective thermal to selective catalytic processes. Alloying of metal catalysts with promoter elements presents a particularly relevant example of better catalyst design through manipulation of materials chemistry.…”

Synthesis of embedded iron nanoparticles in Fe3C-derived carbons

“…[11,[13][14][15][16][17] There has been growing interest to functionalize CDCs with metal nanoparticles. [18][19][20] Many traditional methods focus on impregnation of the metal by wetting the adsorbent with a solution containing the metal precursor. However, this often results in limited control of metal particle size, pore blockage of the carbon support, and weak support-metal interactions, particularly within templated pore architectures that rely on interconnecting pores.…”

“…[21] As such, many new approaches have focused on in-situ approaches to limit pore blockage and maximize dispersion. [20,22] Still these approaches can require lengthy synthesis procedures, and have motivated this study to investigate the viability of the metal in the metal carbide as an active site.…”

Au encapsulated into Al-MCM-41 mesoporous material: in situ synthesis and electronic structure

“…Therefore, the direct incorporation method usually generates a high dispersion of metal nanoparticles and regular shapes and pores. 22,23 Recently, several noble metals (Au, Pt, Ag) have been successfully incorporated into the mesoporous materials SBA-15 by an in situ reduction method. However, the mesoporous matrixes used in these work were mostly constructed by pure silica materials when using chemical salts as sources.…”