In the last few years, the invention of
a new group of mesoporous silicate or aluminosilicate molecular sieves, which is
called M41S, has been receiving much attention in some areas of nanotechnology,
chemical, engineering and physical sciences. M41S is broadly classified into four
main categories including ordered hexagonal pore structure of MCM-41, cubic pore structure of MCM-48, lamellar of MCM-50
and unstable molecular organic octomer. However, MCM-41
is the most highly essential for scientists because it provides a lot of advantages.
is absolutely tremendous because it is a good catalyst for some of the chemical
reactions, for examples dimerization–hydrogenation of ?-pinene (Zhang et al,
2017), oleic acid esterification (Wang and Yu, 2016) and phenol hydroxylation
with H2O2 (Zhang et al, 2010). The catalytic performance
of its material is especially related to the number of Bronsted acid sites and
Lewis acid sites on its surface. These sites are
like fabric because it is a place where the chemical reaction is conducted.
The higher number of acidic sites is on the surface, the faster the chemical
reaction is. Zhang et al (2017) recently investigated the result of the introduction
of palladium (Pd) and aluminum (Al) into MCM-41
pores. By shaking MCM-41 with Pd
and Al solution for 1 hour, finely dispersed Pd and Al species on the surface
of MCM-41 were obtained which
exhibited strong Bronsted acid sites and Lewis acid sites. The catalytic activity
of Pd-Al-MCM-41 was tested for the
one-pot dimerization hydrogenation of ?-pinene at 140 oC with 2 % dosages.
This material shows high catalytic activity which is faster than the bulk Pd or
Al catalyst and yields of the dimer is 63.9 %. Moreover, the catalytic activity
of its material is particularly associated with its owned thermal stability needed
for the high temperature chemical reaction. Qin et al (2016) observed that the addition
of Ni into the MCM-41 structure resulted
in the raising of thermal stability of MCM-41.
The catalytic ability of the Ni-MCM-41
for curmene cracking was observed giving the value of conversion rate of 54.5
%. Furthermore, the choosing of MCM-41
as catalyst especially in pharmaceutical and agrochemical sciences for the finely
chemical production and the building block synthesis is done largely due to
offering lots of benefits such as easy separation, simple recovery and easy elimination
from the hazardous chemistry.
Another useful of MCM-41 is an adsorbent
molecule that can be widely used for selective adsorption of many organic and
inorganic pollutants from water. A number of studies have been exhibiting that the
adsorption capacity of MCM-41 is not only affected by large pore volume, large
surface area and pore uniformity degree of MCM-41 but also by functional groups
on the surface. Costa et al (2015) synthesized MCM-41 using tetraethylorthosilicate
(TEOS) and surfactants mixture tetradecyltrimethylammonium bromide (TDMABr) and
cetyltrimethylammonium bromide (CTABr). TDMABr-CTABr-MCM-41 was examined for CO2
adsorption. The value of adsorption capacity is 0.62 g CO2/adsorbent.
One of the members of M41S material,
MCM-41 gives many advantages both good catalyst and adsorbent molecule. The number
of Bronsted acid sites, Lewis acid sites and functional groups on the surface,
thermal stability, large pore volume, large surface area and pore uniformity
degree of MCM-41 are highly conducive for catalysis and adsorption.