Nitrogen, Phosphorus, and Sulfur Co‐Doped Hollow Carbon Shell as Superior Metal‐Free Catalyst for Selective Oxidation of Aromatic Alkanes

Abstract

Metal-free heteroatom-doped carbocatalysts with a high surface area are desirable for catalytic reactions. In this study, we found an efficient strategy to prepare nitrogen, phosphorus, and sulfur co-doped hollow carbon shells (denote as NPS-HCS) with a surface area of 1020 m(2) g(-1). Using a poly(cyclotriphosphazene-co-4,4'-sulfonyldiphenol) (PZS) shell as carbon source and N, P, S-doping source, and the ZIF-67 core as structural template as well as extra N-doping source, NPS-HCS were obtained with a high surface area and superhydrophilicity. All these features render the prepared NPS-HCS a superior metal-free carbocatalyst for the selective oxidation of aromatic alkanes in aqueous solution. This study provides a reliable and facile route to prepare doped carbocatalysts with enhanced catalytic properties.

Metal–polydopamine frameworks and their transformation to hollow metal/N-doped carbon particles

“…[1][2][3][4][5][6][7] In particular, nanoporous carbon materials with hollow structures can further enhance their performance in many applications. [8][9][10][11][12][13] In general, hollow carbon nanoparticles are synthesized via the templating technique, which usually involves the coating of a carbon precursor on a pre-synthesized solid core template (such as silica colloids, polystyrene spheres), followed by carbonization and selective removal of the templates. [14][15][16] However, the removal of the template is time-consuming and involves some harmful solvents (such as HF).…”

“…42 Nevertheless, hollow carbon materials directly derived from metal-organic coordination complexes have been rarely reported. 9,23 MOFs are attractive candidates for the synthesis of metal-carbon composites due to their diverse compositions with various metal ions and organic ligands. [43][44][45][46] For example, zeolite imidazolate frameworks (ZIFs), a subclass MOFs, are the most commonly-used precursor for carbon-based catalysts as they are rich in carbon, nitrogen and transition metal elements, which could form M-N-C active sites after carbonization to improve the catalytic performance in electrochemical catalysis.…”

Secondary‐Component Incorporated Hollow MOFs and Derivatives for Catalytic and Energy‐Related Applications

“…As an example, the beforementioned POM-incorporated Fe/Co-BTC nanotubes exhibited higher catalytic activity toward aerobic oxidation of thiophenol to diphenyldisulfide comparing with monocomponent MOF and POM counterparts, while Co, Fe centers, and POM unit could all serve as catalytic sites. [55] Copyright 2016, Wiley-VCH. For example, above-mentioned Zn/ Fe III -MOF-5 hollow octahedrons can encapsulate the PdCu dendrites with maintained morphology (Figure 5a), [26] [26] Copyright 2014, Wiley-VCH.…”

Trisulfide‐Bond Acenes for Organic Batteries

“…[6] Some organic conductive polymers have even higher theoretical and experimental capacities.H owever, they are strongly dependent on the doping level to change their redox properties.F urthermore,i ti sd ifficult to purify these polymers,a nd the low material purity may induce adecrease in performance.Also,the mechanism study is quite difficult for polymers since many experimental parameters can affect the performance.T he molecular design of small organic molecules offers an efficient way to realize expected properties from both theoretical calculations and experimental results. [9] 2) Low solubility in organic electrolytes and high cycling stability.Some experimental results indicate that some small organic molecules are easily dissolved in organic electrolytes,which results in abad cycling stability.Inaddition to polymerization, enhanced p-conjugation in both backbone and side chains is apromising way to decrease the solubility of small organic molecules and to increase the conductivity which can improve the performance.3 )Systematically controllable large-scale synthesis with reproduced uniformity. Thei nclusion of functional heteroatoms in small organic molecules is agood approach to improve the performance and to obtain good material reproducibility and stability.…”