The document summarizes research into synthesizing manganese oxide nanoparticles through various chemical reactions. It describes reacting potassium permanganate with alcohols and di-alcohols in the presence of carboxylic acids. A series of experiments were conducted using different alcohols, di-alcohols and carboxylic acids. The experiments aimed to produce nanostructured materials with interesting morphology, small particle size, and high surface area. Scanning electron microscopy images of some products showed spheres and nanostructures, though not all reactions yielded useful materials. The research seeks to develop manganese oxide materials for applications in batteries, catalysis and toxic waste removal.

1. Synthesis of Manganese Oxide Nanoparticles Via the Reaction
of Butyric Acid and Potassium Permanganate with Di-Alcohols
Chemistry 391
Milton Garrett III
Connecticut College 14’
Professor Stanton Ching, Project Advisor
Department of Chemistry, Connecticut College

2. Introduction
Manganese oxides are of particular interest to many scientists for its unique applicable
chemistry in the self assembly of hierarchical nanostructures. The structure and properties of
these manganese oxides allow for the applicable use of battery power technology, toxic waste
removal, and catalytic processes. An interesting feature of these materials is their relatively large
surface area. Manganese is of particular interest because of its ability to be easily oxidized thus
hosting a changing oxidation state. The manganese in the manganese oxide materials also have
the ability to easily change its oxidation state, which is relevant in electrical conductivity. Large
surface area is desirable because it provides more places for catalytic activity to occur and the
exchange of ions to take place. An example would be the toxic waste removal of CO by
conversion to CO2 and NO removal through conversion to NO2. Ions can interchange between
the manganese oxide materials because of its micropourisity.
Stanton Ching, Powerpoint 2010
Figure 1, Removal of CO and conversion to CO2 on manganese oxide surface
The synthesis of inorganic manganese oxide materials yields small microporous
nanoparticles. The chemistry behind the synthesis of these nanoparticles is interesting as there
CO
MnO2
CO2
O2

3. are many routes to producing manganese oxide products. Routes to synthesizing these materials
are many, some of the most commonly used involve redox reactions with Mn 7+ potassium
permanganate and Mn 2+ salts. Hydrothermal treatment of layered birnessiste structures also
yield porous manganese oxide nanostructures. Another synthetic route is the reaction of a silicon
oxide shell with potassium permanganate and hydrothermal treatment to yield a core shell
consisting both of silicon oxide and manganese oxide. This shell is treated with sodium
hydroxide and silicon etching to yield manganese oxide hollow spheres.1
Studies have proven
that Manganese oxides can also be synthesized by the reduction of Mn 7+ with an organic
reducing agent such as specific carboxylic acids and polyols with sugars resulting in the
formation of sol and gel material. Recent studies of this sol and gel route also indicate that the
reduction of the Mn7+ permanganate with some organic reducing agents can yield microporous
manganese oxides in a “one pot reaction.” Studies have proven success in synthesizing the
favored microporous manganese oxide materials through the reaction of a manganese compound
such as permanganate and an organic reducing agent in the presence of a carboxylic acid . It is
believed that the carboxylic acid directs the formation of manganese oxide tunnel structures .
The synthetic route that will be used in this project involves the formation of manganese oxides
with interesting morphology through a “one-pot” reaction synthesis.
Manganese oxides have unique architectural structures, physical appearances, and
morphology that allows for useful applications. The building blocks for forming most manganese
oxide structures start with a MnO6 octahedron. This octahedron can be assembled by the sharing
of edges of octahedra to form large molecules with different structural arrangements that are
categorized as tunnels. The tunneled manganese oxides are crystallized and the manganese in
1
Ching PPT, Li and co-workers J. Power Sources 2009, 193, 939.

4. these materials often possess mixed valencies . 2
The tunnels are constructed with single, double
or triple chains of edge sharing MnO6 octahedra to produce structures that resemble tunnels with
a square /rectangular cross-section and sheets of concentric nano-size layers called birnessites .
3
The inside of these layered tunnels contain water molecules as well as cations. This unique
physical property is useful as the layered tunnels allow for ion exchange and storage of cations to
stabilize the charge of the manganese oxide material.4
Past studies have shown that these
materials yield products with high surface area that come as a result of the aggregation of
particles, interestingly enough to sometimes produce hollow spherical structures. The high
surface area materials are desirable because they are the site for catalytic activity, ion exchange,
and potential for microporousity . The significance of looking for the hollow spheres and a flat
surface is for uniformity in the product at the microscopic level.
Figure 2: Structures of Manganese Oxides, Birnessite, Hollandite (Cryptomelane), and Todorokite respectively.
The objective of this independent study is to test potassium permanganate (KMnO4) with
alcohols, di-alcohols, in the presence of a carboxylic acid using a one-pot reaction mechanism.
The purpose of these experiments are to synthesize nanostructured materials that show
interesting morphology as it relates to small particle size, hollow and spherical architecture, and
2
Angew. Chem. Int. Ed. 2008,
3
Proc.Natl. Sci. Acad. USA 96 (1999), Vol. 96 pp. 3447-3454,
4
Chem. Mater., Vol. 10, No. 10, 1998

5. potential for high-surface area materials. The manganese oxide materials produced in our lab are
different from those discussed in similar study in that the materials are amorphous and have no
definite layered structure or lattice pattern. A recent study in our lab synthesized useful
manganese oxides using manganese sulfate and permanganate in the presence of a carboxylic
acid through a one-pot route. 5
The most recent work in our lab relating specifically to this
project was the synthesis of manganese oxides using butanol and carboxylic acids. 6
Modifications to the butanol project involved changing the carboxylic acid as well as changing
the alcohol and each of their concentrations in a reaction respectively. The same one-pot
mechanism/idea will be used in this project’s experimental approach using alcohols and di-
alcohols with potassium permanganate in the presence the carboxylic acid, butyric acid (BA),
maleic acid (MA), Glutaric Acid (GA), Pimelic Acid (PA), and Succinic Acid (SA) .
Synthesizing manganese oxides using dialcohols would be of interest in this project because of
the two hydroxyl functional groups in the compound. One could assume that the presence of two
hydroxyl functional groups would yield useful manganese oxide products. The basis for this
rationale would be because of recent success in our lab in synthesizing desirable manganese
oxides using butanol as a reducing agent.
Experimental Section
The general/standard procedure for the synthesis of manganese oxides in the Ching lab
lab involves a reaction between MnSO4 and KMnO4 in the presence of a carboxylic acid (butyric
acid). To start, 1 mmol (.254 grams) of MnSO4 is dissolved in a beaker filled of 25 mL of
distilled water. Then, 2.3 mL (24mmol) of butyric acid is added to MnSO4 solution and is stirred
5
Chem. Commun., 2011 47,8286-8288)
6
Ian Ritcher and Kathryn Tutunjian (Unpublished Work)

6. vigorously with a magnetic stirrer. One mmol of KMnO4 (.158 grams) is added to a beaker of 25
mL of distilled water and stirred vigorously to dissolve any solid permanganate. The
permanganate solution is added to the manganese sulfate solution and the mixture of both
solutions is stirred vigorously. A brown solid is formed and the mixture is stirred for 15 minutes.
The solid was isolated by filtration, washed three times, then dried at 110 o
C.
Generally, manganese oxide materials are analyzed through characterization imaging,
determination of manganese content in the samples, and testing for surface area.
Characterization of manganese oxide is done through Scanning Electron Microscopy (SEM),
Transmission Electron Microscopy (TEM), Thermogravimetric Spectrospescopy, (TGA), and
Atomic Absorption (AA). Determining the content of manganese in the samples are done by
performing oxidation states and surface area analysis is done by Brunauer-Emmet Teller (BET)
analysis . TGA, SEM, and TEM were performed on manganese oxide materials synthesized in
this specific project. Analysis of manganese oxides materials via reactions with butanol have
calculated the oxidation state of manganese in the materials to between 3+ and 4 + .
In the reactions of this project, KMnO4 is reacted with an alcohol/dialcohols in the
presence of a carboxylic acid. A series of reactions with butyric acid and the following alcohols
were performed: allyl-alcohol, 1,4 -butanediol, 1,8- octanediol. Three experiments were
performed with 1,4 –butanediol. The detailed synthesis for each reaction involving 1,4-
butanediol and each trial is described in the table below in Figure 3.

7. 1,4 -Butanediol with BA
1,4 -
Butanediol
Moles of
KMn04
Carboxylic
Acid
Moles of
Carboxylic Acid
Moles of
Alcohol
Volume of
Distilled
H20
Reaction
Time *
Mole Ratio/ Unique OBS
Trial 1 1mmol
.158g
Butyric
Acid
24 mmol
(2.3mL)
6mmol
(.55mL)
50 mL Fast Moles OH: Mn = 6:1
Trial 2 1 mmol
.158g
Butyric
Acid
24mmol
(2.3 mL)
12mmol
(1.1mL)
50 mL Very slow
Let stir over
weekend
Moles OH: Mn = 12:1
Trial 3 1 mmol
.158g
Butyric
Acid
24mmol
(2.3 mL)
24mmol
(2.2mL)
50 mL Normal Moles OH: Mn = 24:1
Figure 3, 1,4 -Butanediol with BA *Normal reaction times occur between 9-15 minutes
1,8 -Octanediol with BA
Seven experiments were performed with 1-8 octanediol. The detailed synthesis for each
reaction and each trial is described in the table below in Figure 4.
1,8 -
Octanediol
Moles of
KMn04
Carboxylic
Acid
Moles of
Carboxylic Acid
Moles of
Alcohol
Volume of
Distilled
H20
Reaction
Time *
Unique OBS/ Mole ratio
Trial 1 1mmol
.158g
Butyric
Acid
24 mmol
(2.3mL)
6mmol
(.885grams)
50 mL Fast
Moles OH: Mn = 6:1
Trial 2 1 mmol
.158g
Butyric
Acid
12mmol
(1.1 mL)
6 mmol
(.885grams)
75mL Normal Moles OH: Mn = 6:1
Trial 3 1 mmol
.158g
Butyric
Acid
6 mmol
(.55mL)
12mmol
(1.58
grams)
75 mL Normal Moles OH: Mn = 12:1
Trial 4 1 mmol
.158g
Butyric
Acid
6mmol
(.55mL)
12mmol
(1.58 grams)
40ml Normal Moles OH: Mn = 12:1
Trial 5 1 mmol
.158g
Butyric
Acid
12mmol
(1.1mL)
12mmol
(1.58 grams)
50 mL Normal Moles OH: Mn = 12:1

8. Trial 6 1 mmol
.158g
Butyric
Acid
12mmol
(1.1 mL)
12mmol
(1.58 grams)
75 mL Normal Moles OH: Mn =12:1
Trial 7
Control
1mmol
.158g
None None 6 mmol
.885grams
50 mL Normal Moles OH: Mn = 6:1
Figure 4, 1,8 -Octanediol with BA *Normal reaction times occur between 9-15 minutes
Seven reactions were done with allyl alcohol. The detailed synthesis for each reaction and
each trial is described in the table below in figure 5
Allyl
Alcohol
Moles
of
KMn04
Carboxylic
Acid
Moles of
Carboxylic Acid
Moles of
Alcohol
Volume of
Distilled
H20
Reaction
Time *
Mole Ratio/ Unique OBS
Trial 1 1mmol
.158g
Butyric Acid 24 mmol
(2.3mL)
2mmol
.14mL)
50 mL Normal Moles OH: Mn = 2:1
Trial 2 2 mmol
.316g
Butyric Acid 24 mmol
(2.3mL)
1 mmol
(.07mL)
50 mL Normal Moles OH: Mn = 1:2
Trial 3 4 mmol
.632g
Butyric Acid 24 mmol
(2.3mL)
2mmol
(.14mL
50 mL Normal Moles OH: Mn = 2:4
Trial 4 2 mmol
.316g
Butyric Acid 24 mmol
(2.3mL)
2mmol
(.14mL)
50 mL Normal Moles OH: Mn =2:2
Trial 5 1 mmol
.158g
Butyric Acid 24mmol
(2.3mL)
1mmol
(.07mL)
50 mL Normal Moles OH: Mn =1:1
Trial 6 1 mmol
.158g
Butyric Acid 24mmol
(2.3mL)
.5 mmol
(.035mL)
50 mL Normal Moles OH: Mn = .5 : 1
Trial 7
Control
1mmol
.158
None None 1 mmol
(.07mL)
50mL Normal Moles OH: Mn =1:1
Slow reaction
Figure 5, Allyl Alcohol with Butyric Acid *Normal reaction times occur between 9-15 minutes

9. Butanol with varying Dicarboxylic acids
Butanol was reacted with KMnO4 and the following carboxylic acids: pimelic acid (PA),
succinic acid (SA), maleic acid (MA), glutaric acid (GA). The detailed synthesis for each
reaction and each trial is described in the table below in figure 6
Butonal Moles
of
KMn04
Carboxylic
Acid
Moles of
Carboxylic Acid
Moles of
Alcohol
Volume of
Distilled
H20
Reaction
Time *
Unique OBS
Trial 1 1mmol
.158g
Glutaric Acid 12mmol
(1.58 grams)
12mmol
(1.1mL)
50 mL Normal
Trial 2 1 mmol
.158g
Maleic Acid 12mmol
(1.41 grams)
12mmol
(1.1mL)
50 mL Very fast Mn 2+ solution quickly,
brown, to yellow, to
clear color in seconds
Trial 3 1 mmol
.158g
Pimelic Acid 12mmol
(1.92 grams)
12mmol
(1.1mL)
50 mL Normal
Trial 4 1 mmol
.158g
Succinnic Acid 12mmol
(1.41 grams)
12mmol
(1.1mL)
50 mL Normal
Figure 6, Butanol with Varying Carboxylic Acids *Normal reaction times occur between 9-15 minutes

10. Results and Discussion
Results indicate that the series of experiments with 1,4 -butanediol aren’t as effective in
reproducing the desired manganese oxide. figure 7 shows SEM characterization of the 1,4 -
butanediol experiment that yield some small spherical nanostructures. Figure 7 shows edges of
the spheres to overlap. Although figure 7shows a lack of uniformity in the product and
disproportionate spherical nanoparticles , because of its nanostructure this sample would be a
good candidate for BET analysis in the future. Most of the reactions with 1,4 -butanediol
occurred quickly and the reaction took place within 8-15 minutes.
Figure 7. 1,4-Butanediol with Butyric Acid , Trial 2 (1mmol KMnO4 12 mmol of Alcohol , 24 mmol of BA)
Butanol
The butanol series of reactions did not produce interesting results at all as many of the
characterization images shows the morphology of these products not to be useful. Figure 8 shows
a sample of Pimelic acid (PA), trial 3 in the butanol experiments, with a surface of large non-
uniformed particles. The surface of the large particles appear to be rough and non-concentric.

11. The observations of this sample indicate that there is an absence of visible hollow spheres, thus
showing that there is no potential for surface area in this material. The butanol reaction with
maleic acid (Trial 2) yielded a result that was observed as a solution of manganese 2+ as the
product. The color of this solution changed from brown to yellow, to clear in a matter of a few
seconds.
Figure 8. Butanol with Pimelic acid (Trial 3, 12 mmol PA, 12 mmol Butanol,1mmol KMnO4)
1,8-Octanediol
Materials synthesized from 1,8- octanediol yielded products with spherical and hollow
morphology. Figure 9 is a SEM image from trial 1of the 1,8-octanediol experiments that shows
nanoparticles that are uniformed and spherical. This reaction was reproduced however,
characterization of the reproduced sample did not show the same features in SEM
characterization as the original sample; hence it was noted that this experiment could not be
routinely reproduced.

12. Figure 9. 1,8-Octanediol with Butyric Acid , Trial 1, (1mmol KMnO4 , 6 mmol of Alcohol , 24 mmol of BA)
The reaction for trial 1 was fast and yielded interesting results. From the results one can conclude
that the excess of butyric acid (24 mmol) with 1,8-octanediol (6mmol) in the presence of
(1mmol) permanganate yields small spherical nanostructures products. Results indicate that
increasing the concentration of 1,8-octanediol had no affect on morphology of the sample. Trials
3 and 4 show the comparison in synthetic conditions for increasing the concentration of 1,8 -
octanediol.
The SEM images of trial three in this experiment show manganese oxides that are made
up of small spheres. The SEM image of trial 3 is shown in figure 10. The size of these particular
spherical nanoparticles appear to be much smaller than the nanoparticles produced in other
experiments. The surface of this product is uniform, hence these products would be a good
candidate for BET surface area analysis.

13. Figure 10, 1,8 -Octanediol (Trial 3, 6mmol BA, 12 mmol 1,8-octanediol, 1mmol KMnO4)
TGA analysis of trial 3 is shown in figure 11. The analysis shows a significant amount of
product weight loss at a rather low temperature. A sharp decline in weight loss occurs at around
220 o
C ; weight loss at this temperature may be due to the burning of hydrocarbons in the
material.

14. Figure 11, TGA Analysis of Trial 3

15. Figure 12 shows SEM characterization of the control for this experiment. The images
from the control indicate that without the presence of butyric acid, the surface of the manganese
oxide materials would not be spherical or small in particle size.
Figure 12, 1,8 -Octanediol (Trial, 6 mmol 1,8-octanediol , 1mmol KMnO4, no BA )
Possible reasons why there are differences between materials of the 1,4- butanediol and
1,8 -octanediol materials is because of the number of methylene groups in between in each
alcohol. Based upon characterization results, 1,8 –octanediol yields products with better
morphology.
Allyl alcohol
Allyl alcohol is very reactive and has the potential to be a dangerously flammable
reactant, so the concentration used in the series of reactions was very low. The experiments with
allyl alcohol produced interesting results, however the design of the experiment could have had a
better systemic approach. Reasons why allyl alcohol produced such interesting results may be

16. because of the manganese having possible reactivity with the double bond reacting. Figure 13
shows trial 5 in the experiment, 1mmol KMnO4, 1mmol of allyl alcohol, and 24 mmol of BA.
Figure13. Allyl Alcohol Trial 5 (1 mmol of Alcohol , 24 mmol BA, 1mmol KMnO4 in 50 mL of water)
TGA analysis was done on trial 5 and is shown in figure 14. There is a gradual decrease
in product weight until about 480 o
C; this loss of weight may be due to the loss of water and
lattice oxygen in the material. Similar projects in our lab have shown the thermal stability of
manganese oxides materials using MnSO4 and KMnO4 to resemble the TGA curve depicted in
figure 14.

17. Figure 14, TGA Analysis of Trial 5

18. Figure 15 shows the reaction of trial 4 in which 2 mmol of permanganate react with
2 mmol allyl alcohol, and 24 mmol of BA. The manganese oxides in this reaction show the best
morphology as the surface shown is made up of many uniform nanoparticles that also appear to
be hollow.
Figure15. Allyl alcohol with butyric acid. (Trial 4, 2mmol of KMnO4 , 2mmol of allyl alcohol, )
Figure 16 shows a TEM image of trial 4, the surface is composed of thin fibrous
nanaoparticles definitely useful for applications of surface area. Under high magnification, the
surface of this sample looks hollow and the shape of the particles on the surface look fibrous;
hence indicating small uniform manganese oxide nanoparticles. This sample is a good
candidate for BET surface area analysis.

19. Figure 16. Allyl alcohol with butyric acid. (Trial 4, 2mmol of KMnO4 , 2mmol of allyl alcohol )
Figure 17 shows an SEM of allyl alcohol with no butyric acid (Trial 7). From this image,
one can deduce that without the presence of butyric acid, the surface of the manganese oxide
materials would not be spherical or small in particle size.
Figure 17. Allyl alcohol with butyric acid (Trial 4, 1mmol of KMnO4 , 1mmol of allyl alcohol, no BA)

20. Conclusion
Results from this project support the argument that the presence of a carboxylic acid
plays a huge role in directing the formation of hierarchical manganese oxide nanostructures. In
the experiments with 1,8-octanediol and allyl alcohol, characterization of the control for both
experiments lack small uniform nanoparticles in their morphology, thus supporting the argument
that carboxylic direct the formation of hollow spherical manganese oxides. Results from the
butanol experiments indicate that the selection of an appropriate carboxylic acid and relative
concentration play a huge factor in determining the outcome of the product. In comparison to
recent research with butanol, the dicarboxylic acids used in this experiment produced worse
results than a carboxylic acid such as butyric acid. The results of this project study indicate that
the smaller more uniform manganese oxide particles occur in di-alcohol reactions that have
more methylene groups in between each alcohol functional group. Comparison between the
characterization results of 1,8-octanediol and 1,4-butanediol support this experimental
hypothesis.
In the 1,8-octanediol reaction , the best results occurred when the concentration of
alcohol was between 6 and 12 mmols. Allyl alcohol yielded manganese oxides with the most
interesting architecture even at a substantially low concentration in comparison to the 25x mmol
excess amount of carboxylic acid. The success of using di-alcohols in this project is useful to
our laboratory research because characterization of these samples indicate the product’s potential
for high surface area and catalytic activity. Experiments with allyl alcohol show similarly
interesting morphology in reactions where 1mmol and 2mmol of potassium permanganate were
reacted. Future work on reactions with alcohol might include trying different experimental

21. approaches with 1-8 octanediol and allyl alcohol. Perhaps, increasing the amount of allyl alcohol
and adjusting the synthetic conditions would yield samples with even more interesting results.
As for the butanol series, perhaps trying another carboxylic acid, or decreasing the amount of the
carboxylic acid will affect the morphology of the samples.

22. Reference
1 Ching PowerPoint, Li and co-workers J. Power Sources 2009, 193, 939.
2 A Core-Corona Hierarchical Manganese Oxide and its Formation by an
Aqueous Soft Chemistry Mechanism, David Portehault, Sophie Cassaignon, Nadine
Emmanuel Baudrin, and Jean Pierre Jolivet, www. Angewandte.org , Angew.
Chem. Int. Ed., 47, 6441-6444 , 2008
3 Manganese Oxide minerals: Crystal structures and economic and environmental
significance, Jeffery E.Post, Proc.Natl. Sci. Acad. USA 96 (1999), Vol. 96 pp.
3447-3454, March 1999
4 A Review of Porous Manganese Oxide Materials Stephanie L. Brock, Niangoa
Duan, Zheng, Rong Tian, Oscar Giraldo, Hua Zhou, and Steven Suith, Department
of Chemistry, Institute of Materials Science, and Department of Chemical
Engineering, University of Connecticut, Storrs, Connecticut 06269-4060,Suib
Chem. Mater., Vol. 10, No. 10, 1998 ,U-60,
5 Self –assembly of manganese oxide nanoparticles and hollow spheres. Catalytic
activity in carbon monoxide oxidation. Stanton Ching , David A. Kritz, Kurt M.
Luthy, Eric C. Njagi, Steven L. Suib ,Chem. Commun., 2011 47,8286-8288) Royal
Society of Chemistry 2011
6 Butanol and Carboxylic acid Synthesis of Manganese Oxides, Connecticut
College, Ching Lab, Ian Ritcher and Kathryn Tutunjian, (Unpublished Work) 2011