Controllable preparation of highly dispersed TiO₂ nanoparticles for enhanced catalytic oxidation of dibenzothiophene in fuels

Abstract

The aggregation of nanoparticle catalysts is one of the main problems in catalytic reactions. In this study, a series of TiO 2 nanoparticle catalysts with various dispersions were prepared and applied in the catalytic oxidation of dibenzothiophene (DBT) systems. Compositions and structures of the as-prepared samples were analyzed by means of wide-angle X-ray diffraction, Raman and X-ray photoelectron spectroscopies. The dispersions of TiO 2 nanoparticles were controlled by calcining at various temperatures and verified using transmission electron microscopy. It was found that the activities of TiO 2 nanoparticles in the catalytic oxidation of DBT were positively correlated with the dispersions. TiO 2 nanoparticles calcined at 500°C (500-TiO 2 ) showed the best catalytic activity and the oxidation of DBT reached 99.8% under mild conditions. Based on the results of GC-MS analysis, radical trapping experiments and electron spin resonance spectra, • O 2 − radicals were proved to be the main active species in the oxidation process, and a mechanism is proposed. Meanwhile, the recycling performance of 500-TiO 2 was investigated, and no obvious decrease was observed after six recycles.

Dispersing TiO2 Nanoparticles on Graphite Carbon for an Enhanced Catalytic Oxidative Desulfurization Performance

“…Based on the results and discussions above, a possible mechanism on the oxidation of DBT was put forward and displayed in Scheme . First, TiO 2 and GC possessed strong adsorption capacities to DBT, which were beneficial to the enrichment of DBT on the surface of the supported catalyst. , Simultaneously, H 2 O 2 interacted with TiO 2 on the surface of GC to generate • O 2 – which then reacted with DBT to form DBTO 2 until DBT was totally oxidized. Compared with DBT, the polarity of the oxidative product was enhanced.…”

“…First, amorphous TiO 2 was synthesized from titanium isopropoxide according to the reported literature. 44 Then, the supported catalyst precursors were prepared. A certain amount of amorphous TiO 2 obtained above and GC were added into a 250 mL beaker, and 30 mL anhydrous ethanol was added and stirred for 1 h. The mixture was ultrasonicated for 30 min before being transferred to a Teflon-lined autoclave.…”

“…First, amorphous TiO 2 was synthesized from titanium isopropoxide according to the reported literature . Then, the supported catalyst precursors were prepared.…”

Improved photocatalytic performance of anatase TiO2 synthesized through ethanol supercritical drying technique

“…Nano‐sized titanium dioxide (TiO 2 ) as a “green” photocatalyst is a benchmark material among semiconducting photocatalysts because of its high photocatalytic activity, chemical stability, and favorable optoelectronic properties. It shows the advantages of stable physiochemical properties, abundant reserves, non‐toxicity, environmental friendliness, and low cost; thus it is extensively applied in many fields such as the degradation of organic pollutants, water splitting, electrocatalysis, and solar cells . For the effective photocatalytic degradation of organic pollutants, high‐performance photocatalysts should better satisfy the requirements of wide spectral response range, rapid separation of photogenerated carriers, and more surface‐exposed active sites.…”

Amorphous TiO2‐Derived Large‐Capacity Lithium Ion Sieve for Lithium Recovery

“…The amorphous TiO 2 was prepared by the following steps [26]. Deionized water (1 mL) and absolute ethanol (100 mL) were added into a 250-mL beaker and the mixture was magnetically stirred.…”