Tailoring mesoporosity of poly(furfuryl alcohol)-based activated carbons and their ability to adsorb organic compounds from water
Journal of Material Cycles and Waste Management
https://doi.org/10.1007/s10163
Tailoring mesoporosity of poly(furfuryl alcohol)-based activated carbons and their ability to adsorb organic compounds from water
Ewa Lorenc‑Grabowska 0
Piotr Rutkowski 0
0 Department of Polymer and Carbonaceous Materials, Faculty of Chemistry, Wrocław University of Science and Technology , Gdańska 7/9, 50-344 Wrocław , Poland
1 Ewa Lorenc-Grabowska
In this work it was shown that polymers can be recycled into a promising adsorbent for organic dyes and phenols waste removal. For this, a series of activated carbons (ACs) were produced from mixture of ferrocene or titanium acetylacetonate with poly(furfuryl alcohol) (PFA) by steam activation. The introduction of ferrocene as Fe precursor was found to be an efficient catalyst in mesoporosity development during carbonization and subsequent steam activation at 850 °C, whereas the polymer based only and titanium-doped ACs are typically microporous. The porous structure parameters were determined from nitrogen adsorption isotherms measured at 77 K. Scanning electron microscopy was applied to monitor the metal distribution of metal-loaded char and the surface morphology of activated carbons. The adsorption capacity was found to be dependent mainly on pore size distribution. In the case of phenol adsorption, the adsorption was defined by volume of pore with size 0.8-1.4 nm; whereas, for Congo red best fit was observed for volume of pore with size 2-5 nm.
Poly(furfuryl alcohol); Gasification; Metal catalyst; Phenol; Congo red
Introduction
The constant development of civilization leads to expansion
of problems related to municipal solid waste management.
The problems deal not only with collection, transport,
processing or storage, but also with the disposal of waste and
secondary pollution of landfill. An interesting concept of
reducing the waste is the production of activated carbons
(ACs) from solid waste. It allows to utilize the waste and
the obtained adsorbent can be used for further environment
protection. The solid organics with relatively high content of
organic matter including plastic bottles, agricultural or food
waste like straw, rice hull, seeds or fruits shells are some
examples of raw waste materials that can be used to produce
activated carbons [
1–3
]. The ACs can be produced by both
physical and chemical activation. The physical activation of
waste biomass or polymers usually gives activated carbon
with well-developed microporosity and surface are in range
of 400–1100 m2 g−1 [
1, 2
]. The chemical activation results
in visibly larger surface area usually higher than 1500 m2 g−1
[
1, 2
].
Activated carbons (ACs) with specific porous texture
have been of subject of broad interest for many years. There
are many application areas, among them dyes, vitamins,
polymer and bio-molecules adsorption as well as catalyst
preparation, which require well-developed mesoporosity of
carbon material [
4
]. Activated carbons considered as catalyst
carrier, material for hydrogen or methane storage or
electrode material for electric double-layer capacitors or
supercapacitors should also be characterized by high contribution
of mesopores [
5–7
].
The mesoporous ACs might be prepared in several
ways, i.e., by carbonization and activation of proper
carbonaceous precursor or the sol–gel process and the template
method [
8–11
]. Another efficient way for mesoporosity
development is the catalytic gasification [
9–18
]. The
different metals and different forms of the same metal have
different catalytic effects on the gasification of
carbonaceous materials. Generally it is assumed that metal
particles gasify carbon in their immediate vicinity and create
the porosity by forming holes in the carbon matrix.
Transition metal and alkali earth metals have been recognized
as good catalysts for the gasification of carbon materials
to produce activated carbons with developed meso- and
macroporosity [
9–11
]. Activated carbon with a remarkable
contribution of mesopores by steam activation of
different rank coals containing small amounts of metal (Y, Al,
Ti, Zr) acetylacetonate has been known [
12
]. Similarly
calcium or iron have been recognized as effective catalysts
for carbon gasification, promoting the mesopore formation
[
14
]. Iron is one of the metals commonly used in mesopore
formation [
14–18
]. A different form of Fe has been used
to produce the ACs with developed mesoporosity. The
ferrocene was found to be very efficient in mesoporosity
development in pitch [
16, 18
]. Ferrocene was also used to
introduce iron into the PFA but no details about the
porosity development were given [19]. What is more, iron on
activated carbons can be also used as catalyst in catalytic
degradation of polypropylene [
20
].
In recent years there has been a strong emphasis on the
production of ACs from waste products, including waste
polymers and agricultural by-products. Poly(furfuryl
alco (...truncated)