Designed Formation of Polyoxometallate-Based Mesoporous Titania Composites by a Solvent-Free Chemical Self-Assembly Method for Oxidative Desulfurization of Diesels

Abstract

The construction of crystalline TiO 2 with uniform mesoporous architecture plays a key role in its catalytic performance improvement. However, the resulting porous TiO 2 composite is liable to form a disordered pore structure and have a narrow pore size and low porosity after a high-temperature-induced crystallization process, leading to a serious decrease in its catalytic efficiency. Here, a series of polyoxometalate (POM)-modified TiO 2 catalysts with a confined mesostructure have been realized by a rapid and solvent-free self-assembly strategy, oriented by polyethyleneimine (PEI) polymer. TEM and N 2 adsorption analyses demonstrate that the as-fabricated mesoporous composites possess remarkable porous properties (i.e., 260.5 m 2 g −1 and 0.3989 m 3 g −1 ). In addition, the nanomesoscopic structure of catalysts can be further tuned by varying molecular interactions between polyethyleneimine, titanium oligomers, and POMs. The as-fabricated POM-based TiO 2 catalysts provide connected and large mesochannels for reactant molecules in the inner surface and enhance the dispersity of POM species in the TiO 2 matrix, which exhibits excellent catalytic efficiency in the oxidative desulfurization reaction of dibenzothiophene at room temperature.

Solvent-Free Synthesis of Cu/In Dual-Single-Atom-Doped TiO2 for Photocatalytic Reduction of Cr (VI) with High Efficiency

“…The residuary PEI molecules can serve in situ as stabilizers. It maintains the mesostructure to be stable during the crystallization process of titanium species, resulting in producing highly crystalline titanium dioxide with good porosity. , …”

“…It maintains the mesostructure to be stable during the crystallization process of titanium species, resulting in producing highly crystalline titanium dioxide with good porosity. 28,33 The morphology and mesoporous structure of TiO 2 nanomaterials were directly observed via SEM images. The SEM images of the prepared TiO 2 showed the presence of large-scale nanostructures formed by the aggregated nanocrystals (Figure 1a).…”

Efficient Oxidative Desulfurization over [Mo8O26]4–-Based Hybrids: Phase Transfer Catalysis

“…Due to remarkable properties like stable structure, tunable composition, variable solubility in aqueous solutions and organic solvents, and reversible redox activity, 25,26 and ameliorative simple regeneration methods. 27,28 The [C 16 mim] 3 PWO reported by Li et al can eliminate DBT in 40 min. 29 By adopting the same methods, polyoxomolybdatebased hybrid materials also obtained high sulfur removal efficiency.…”

“…Due to the presence of Brönsted acidic groups and imidazolium cations, the TSILs exhibited excellent desulfurization performance. , However, TSILs’ difficult regeneration methods significantly increased costs and constrained industrial advancement. Due to remarkable properties like stable structure, tunable composition, variable solubility in aqueous solutions and organic solvents, and reversible redox activity, , polyoxometalates (POMs) anions are widely employed by researchers to modify the structure of ionic liquids to obtain hybrid materials that display outstanding ODS performance and ameliorative simple regeneration methods. , The [C 16 mim] 3 PWO reported by Li et al can eliminate DBT in 40 min . By adopting the same methods, polyoxomolybdate-based hybrid materials also obtained high sulfur removal efficiency .…”

Synergistic combination: Promising nanoplatform W‐POM NCs@ HKUST‐1 for photothermal and chemodynamic reinforced anti‐tumor therapy

“…Polyoxometalates (POMs) are a class of polymetallic oxygen cluster compounds, [ 17 ] with excellent thermal stability, acid–base stability, and excellent reversible redox properties. W‐POM NCs with excellent photothermal properties have been used for the treatment of tumors by PTT.…”