Graphene
oxide (GO) with three-dimensional network structure (3D
GO) was used as a support, and the monovacant Dawson polyoxotungstate
K10[α-P2W17O61]·20H2O (P2W17) modified with silane coupling
agent was covalently immobilized on 3D GO to prepare a novel heterogeneous
catalyst P2W17/3D GO. Characterizations of the
supported catalyst by FT-IR, UV–vis, XPS, SEM, and TEM confirmed
that P2W17 was immobilized on 3D GO successfully
and well dispersed. The as-prepared catalyst P2W17/3D GO exhibited high catalytic performance in the oxidative desulfurization
(ODS) system of model fuels containing dibenzothiophene (DBT) or tetrahydrothiophene
(THT) using H2O2 as the oxidant. 3D GO exhibits
a certain carrier effect due to its three-dimensional network structure,
the strong adsorption of thiophene compounds through π–π
and S−π interactions, and the acid–base interactions
with 3D GO, which make the ODS performance of P2W17/3D GO much higher than that of P2W17/2D GO
as well as the homogeneous catalyst EPO-P2W17. Various reaction conditions were investigated, and complete oxidative
removal of DBT (500 ppm) and THT (5000 ppm) was achieved at 120 and
30 min under the optimum conditions, respectively. Kinetics studies
were conducted to better understand the oxidation reactions, and the
catalytic oxidation of DBT and THT can both be well described by the
pseudo-first-order model. Moreover, the supported catalyst P2W17/3D GO showed excellent durability even after 5 times
recycling due to covalent immobilization, which makes it a promising
prospect for industrial application.