(717g) A Metal-Organic Framework with Immobilized Ag(I) for Highly Efficient Desulfurization of Liquid Fuels

A Metal-Organic
Framework with Immobilized Ag(I) for Highly Efficient Desulfurization of Liquid
Fuels

Minhui Huang†, Ganggang Chang†, Ye Su†,Huabin Xing†,
Zhiguo Zhang†, Yiwen Yang†, Qilong Ren†,Zongbi Bao*†

Key Laboratory of Biomass Chemical Engineering of
Ministry of Education,°°College of Chemical and Biological Engineering, Zhejiang
University,°°Hangzhou
310027, P. R. China

Abstract

There
is a stringent demand to reduce the sulfur content of diesel fuels to ultralow
levels (~10 ppm) with the aim of lowering the diesel engine's harmful exhaust
emissions and improving air quality. Compared with the hydrodesulfurization
technology, the adsorptive desulfurization is one of the most promising
technologies because of the advantage to remove thiophene
derivatives to produce ultra-clean fuels under mild conditions through
convenient process without the consumption of hydrogen. Metal-organic
frameworks (MOFs), featuring high surface areas, adjustable pore dimensions and
chemical tunability, have received some interests as
novel adsorbents for sulfur removal at moderate conditions. Current research
has been mainly focused on tuning the pores and porosities to enhance their
uptakes, but it is very difficult to remove these compounds to very low
contents because of no specific sites for their strong binding of these thiophene derivatives.

Herein,
we, for the first time, developed a new strategy to incorporate Ag(I) into a
well-known porous metal-organic framework (Cr)-MIL-101-SO₃H for its
highly efficient desulfurization. An optimized
(Cr)-MIL-101-SO₃Ag systematically takes up much more thiophene derivatives than (Cr)-MIL-101-SO₃H,
and about ten times dibenzothiophene°°(DBT)
(31.0 g S/kg MOFs) compared to (Cr)-MIL-101-SO₃H
(2.14 g S/kg MOFs). Furthermore, it has the highest DBT capacity of 5.30 g S/kg
MOF at 10 ppm S of thiophene derivatives among the
best examined MOFs including HKUST-1 and UMCM-150, underlying the very promise
of such immobilizing Ag(I) ions into metal-organic frameworks for ultra-deep desulfuriaztion applications, particularly for diesel and
gasoline that have low sulfur levels. Breakthrough and regeneration studies
indicate that the (Cr)-MIL-101-SO₃Ag is practically feasible for the
practical applications.

Scheme 1 Metal-organic frameworks with ¨CSO₃Ag for adsorptive
desulfurization.

The
following pictures are some relative results:

Figure
1. Adsorption isotherms of (Cr)-MIL-101-SO₃Ag (olive) and
(Cr)-MIL-101-SO₃H (pink) for DBT from n-octane solutions at 30 °C. The curves represent a fit to the Langmuir
equation.

Figure 2.
Breakthrough curves for 0.4 mg/mL DBT in n-octane
for (Cr)-MIL-101-SO₃Ag (olive) and (Cr)-MIL-101-SO₃H
(pink) in n-octane at room
temperature.

Reference

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