The Production and Activation of Carbon Materials from Natural by qingyunliuliu

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									    The Production and Activation of
  Carbon Materials from Natural Sources




                       B. Viswanathan
                             Head
           National Centre for Catalysis Research
           Indian Institute of Technology Madras

Work Shop, 2nd Annual Day Function, National Centre for Catalysis Research
              Special Features of Carbon Materials


                Coordination number is variable/expandable
                Promote new morphologies
                Covalent character retention
                Variable hybridization possible
                Geometrical possibilities/size considerations
                Meta-stable state
                Similar to biological architectures “Haeckelites”


                      Surface Area Modulation

 Carbon is the only material where surface areas can be modulated from few
  m2/g to few 1000 m2/g due to microarchitecture of the pores
 Variety of activating agents can be used
 Functional groups are easily altered
 Functional groups can be easily introduced both chemically as well as by
  anchoring
         Carbon Material from Limonia Acidissima (Wood Apple Shell)
                          Production and Activation
                       Source of carbon     : Shell of wood apple
                       Tree                 : wood apple tree, Bilva patra, Bel, Elephant wood
                       Binomial nomenclature: Limonia Acidissima, Feronia Limonia,
                                              Limonia Elephantum
                       Habitat              : Found all over the deciduous forests in India

                             Shells of wood apple fruit

                        Shells washed in water and dried in air


Procedure:                 Shells charred in muffle furnace
                                           Pyrolysis, Devolatilization, 300 °C, 2 h
                         Charred shells ground and sieved


                       Carbon material as synthesised (char)
                                             Activation with K2CO3
                    Char:K2CO3 = 1:3 wt./wt.% (physical mixing)

                                          Thermochemical activation; N2 atm; 800 °C; 2 h
                 Carbon material with decomposed products of K2CO3
                                             HCl treatment; filtration
                Activated Carbon Material from Limonia Acidissima
             Carbon Material from Myristica Fragrans (Jatikka wood)
                           Production and Activation

                     Source of carbon          : Wood of the tree Jatikka
                     Tree                      : Nutmeg
                     Binomial nomenclature     : Myristica Fragrans
                     Habitat                    : Indonesia, India

                                Wood from Jatikka tree

                   Wood cut into pieces and taken in a glass beaker
                                           Pyrolysis, Devolatilization, 200 °C, 2 h
                        Wood pieces charred in muffle furnace
Procedure:
                           Charred wood ground and sieved

                        Carbon material as synthesised (char)
                                             Activation with K2CO3
                     Char:K2CO3 = 1:3 wt./wt.% (physical mixing)
                                             Thermochemical activation; N2 atm; 800 °C; 2 h
                 Carbon material with decomposed products of K2CO3

                                             HCl treatment; filtration
                  Activated Carbon Material from Myristica Fragrans
                    Phase Structure of Carbon Materials from Limonia Acidissima and Myristica Fragrans

                  2000                                             JCPDS 41-1487


                              (002)
                  1800

                  1600




                                                      (101)
                  1400
Intensity (cps)




                  1200




                                                                                           Intensity (au)
                  1000
                                                                                                                                                    c
                  800                                                      b

                  600
                                                                                                                                                    b
                  400

                  200                                                      a
                                                                                                                                                    a
                    0
                         10   20      30         40           50      60       70
                                                                                                            10   20   30     40      50   60   70       80
                                           2 (degree)
                                                                                                                           2 (degree)

           Carbon materials from Limonia Acidissima                                 Carbon materials from Myristica Fragrans (Jatikka wood)
           (Wood Apple Shell)                                                       (a) As synthesized,
           (a) As synthesized and                                                   (b) Base (NaOH) and acid (HCl) treated and
           (b) Activated with K2CO3                                                 (c) Activated with K2CO3

            Two intense and broad diffraction peaks                                   Presence of diffraction peak at the 2θ value of 12.2
           centered around the 2θ values 24.5 and 43.7                                  indicate regular hexagonal ordering

            The two peaks could be indexed to the                                      The diffraction peak centered around the 2θ value of
           (002) and (101) planes of crystalline                                        23 could be indexed to (002) plane of graphitic
           hexagonal graphite lattice                                                   carbon
                     Carbon materials are produced from Limonia Acidissima and Myristica Fragrans
                        Pore Structure of Carbon Materials from Limonia Acidissima and Myristica Fragrans
                                   N2 adsorption-desorption isotherms and Pore size distribution curves of Carbon Materials
                             250                                                                                                                                                    250

                                                                                                                                                                                    225

                             200                                                                                                                                                                                                                                      As synthesised
                                                                                                                                                                                    200
                                                                                                                                                                                                                                                                      Base and Acid treated
    Volume Adsorbed (cc/g)




                                                                                                                                                           Volume Adsorbed (cc/g)
                                                                                                             Activated with K 2CO 3
                                                                                                                                                                                                                                                                      Activated with K2CO3
                                                                    0.008
                                                                                                                                                                                    175
                                                                                                                                                                                                                                       0.025
                             150
                                           Volume Adsorbed (cc/g)




                                                                                                                                                                                    150                                                                              A s syn th e sise d
                                                                    0.006                                                                                                                                                                                            B a se a n d A cid tre a te d
                                                                                                                                                                                                                                       0.020                         A ctiv a te d w ith K 2 C O 3




                                                                                                                                                                                                           P o re V o lu m e (cc/g )
                                                                                                                                                                                    125
                                                                                                                                                                                                                                       0.015
                                                                    0.004
                             100
                                                                                                                                                                                    100
                                                                                                                                                                                                                                       0.010


                                                                    0.002
                                                                                                                                                                                    75                                                 0.005

                             50
                                                                    0.000                                                                                                           50                                                 0.000
                                                                            0         20    40         60          80             100                                                                                                          0         20    40               60            80     100

                                                                                           Pore Radius (Å)                                                                                                                                                    P o re R a d iu s ( Å )
                                                                                                                                                                                    25
                              0
                                   0.0   0.2                                    0.4          0.6                 0.8                    1.0                                          0
                                                                                                                                                                                          0.0       0.2                                            0.4         0.6                          0.8            1.0
                                                                      Relative Pressure (P/P0)
                                                                                                                                                                                                                                Relative Pressure (p/p0)
                                                                                                                                                                          Myristica Fragrans (Jatikka wood), As synthesized,
                             Limonia Acidissima (Wood Apple Shell),
                                                                                                                                                                          Base (NaOH) and acid (HCl) treated and Activated
                             activated with K2CO3 (Pore size distribution
                                                                                                                                                                          with K2CO3 (Pore size distribution curves are shown
                             curve is shown in the inset)
                                                                                                                                                                          in the inset)
Parameters Characterizing the Porosity of the Carbon Materials:

                                                                     Carbon Materials from                                                    Specific Surface                                  Total Pore volume                                                     Average Pore
                                                                      Myristica Fragrans                                                        Area (m2/g)                                            (cc/g)                                                           Radii (Ǻ)

                                         As synthesised                                                                                             10                                                0.012                                                                                24
                                         Base and acid treated                                                                                      40                                                    0.02                                                                             10
                                         Activated with K2CO3                                                                                       820                                               0.366                                                                                     9
                                                                     Carbon Materials from                                                    Specific Surface                                  Total Pore volume                                                     Average Pore
                                                                      Limonia Acidissima                                                        Area (m2/g)                                            (cc/g)                                                           Radii (Ǻ)
                                         Activated with K2CO3                                                                                       865                                                   0.37                                                                            8.5
Thermal Stability of Carbon Materials from Limonia Acidissima and Myristica Fragrans

               100                                         As synthesised                           100
                                                           Activated with K2CO3
                                                                                                    90
               80
                                                                                                    80

                                                                                                    70
Wt. Loss (%)




                                                                                     Wt. Loss (%)
               60
                                                                                                    60

                                                                                                    50
               40
                                                                                                    40

               20                                                                                   30

                                                                                                    20
                                                                                                                Activated with K2CO3
                0                                                                                   10          Base and Acid treated
                                                                                                                As synthesised
                                                                                                     0
                     100     200   300       400    500    600      700       800
                                                                                                          100     200      300         400   500   600   700   800
                                         Temperature, C                                                                      Temperature, C


                 Limonia Acidissima (Wood Apple Shell),                             Myristica Fragrans (Jatikka wood), As synthesized,
                 As synthesised and Activated with K2CO3                            Base (NaOH) and acid (HCl) treated and
                                                                                    Activated with K2CO3
                  The thermogravimetric curves are recorded in air atmosphere at a heating rate of 20 °C/min

                  Carbon Material (activated) from Limonia Acidissima is thermally stable upto 550 °C

                  Carbon Material (activated) from Myristica Fragrans is thermally stable upto 450 °C

                            Activation improved the thermal stability of the carbon materials produced from
                             Limonia Acidissima and Myristica Fragrans
Surface Functionality of Carbon Materials from Limonia Acidissima and Myristica Fragrans

       100
                                                                                                 FT I IR spectra
                                                                                                                           100
                                                            As synthesised




                                                                                                 -1
                                                                                                 3741 cm
                                                            Activated with K2CO3


       80                                                                                                                  80




                                                                                                           -1
                                                                                                           3855 cm
       60                                                                                                                  60




                                                                                                                                                                                               -1
                                                                                                                                                                                                2303 cm
                                                                                                                      T%
  T%




                                                 -1
                                                 2321 cm



                                                                  -1
                                                                  2851 cm
       40                                                                                                                  40
                                      -1
                                       1731 cm




                                                                            -1
                                                                             2926 cm




                                                                                                                                                                           -1




                                                                                                                                                                                                          -1
                                                                                                                                                                           1705 cm




                                                                                                                                                                                                                     -1
                                                                                                                                                                                                          2850 cm

                                                                                                                                                                                                                     2918 cm
                                                                                       -1
                                                                                       3443 cm
                          -1
                          1620 cm




       20                                                                                                                  20




                                                                                                                                                    -1
                                                                                                                                         -1




                                                                                                                                                                                                                                  -1
                                                                                                                                                    1373 cm
                                                                                                                                                               -1
                                                                                                                                          1219 cm




                                                                                                                                                                                                                                  3440 cm
                                                                                                                                                                                            As synthesised




                                                                                                                                                               1610 cm
                                                                                                                                                                                            Base and Acid treated
                                                                                                                                                                                            Activated with K2CO3
        0                                                                                                                   0
             500   1000   1500          2000               2500             3000            3500           4000                  500   1000                   1500                   2000       2500                3000       3500         4000
                                                                       -1                                                                                                                                  -1
                                    Wave number, cm                                                                                                                      Wave number, cm
         Limonia Acidissima (Wood Apple Shell),                                                                      Myristica Fragrans (Jatikka wood), As synthesized,
         As synthesised and Activated with K2CO3                                                                     Base (NaOH) and acid (HCl) treated and
                                                                                                                     Activated with K2CO3
              1219 cm-1 – C-O stretching in acids, alcohols, phenols, ethers and esters
              1373 cm-1 – In plane bending vibration of C-H in methyl group
              1610 cm-1 – C=O stretching vibration in quinone group
              1705 cm-1 – C=O stretching vibration in carboxylic acid
              2303 cm-1 – Ketone surface groups
              2850 cm-1 – Aliphatic C-H stretching in methylene group
              2918 cm-1 – Aliphatic C-H stretching in methyl group
              3440 cm-1 – O-H stretching mode of hydroxyl groups and adsorbed water
              3741 cm-1 – Isolated O-H groups
                            Free Electron Concentration
        in Carbon Materials from Limonia Acidissima and Myristica Fragrans
                         Electron Paramagnetic Resonance Spectra

                                   As synthesised            0.12                             As synthesised
 0.6
                                   Base and treated                                           Activated with K2CO3
                                   Activated with K2CO3
                                                             0.10
 0.4
                                                             0.08

 0.2
                                                             0.06

 0.0                                                         0.04


 -0.2                                                        0.02


                                                             0.00
 -0.4

                                                             -0.02
 -0.6
    3250      3300       3350        3400             3450       3250     3300      3350        3400             3450

                       H (Gauss)                                                  H (Gauss)

Limonia Acidissima (Wood Apple Shell),                       Myristica Fragrans (Jatikka wood), As synthesized,
As synthesised, Base and acid treated and                    and Activated with K2CO3
Activated with K2CO3 (0.1 g sample in each case)             (0.04 g sample in each case)
 EPR spectra of carbon materials were recorded on X-band spectrometer at room temperature
 The g value of the carbon materials from Limonia Acidissima and Myristica Fragrans is 2.0023,
  exactly matching with the g value of DPPH. This indicates the presence of free electrons in the carbon matrix
 Spin concentration of the char from Limonia Acidissima decreased drastically upon activation
 Spin concentration of the char from Myristica Fragrans completely got quenched upon activation
                        The Marvel of Carbon Morphology

             Carbon Material (Activated) from Myristica Fragrans




        a                                b                                 c
Scanning Electron Microscopic images of carbon material from Myristica Fragrans
activated with K2CO3 at different magnifications; (a) 1200 x, (b) 2000 x and (c) 5000 x
             Well aligned uniform pore net work is developed upon activation

             Pore size - 2.7 μm

             Pore shape - Cylindrical
                                 Conclusion




 Carbon materials with high specific surface area, narrrow pore size
  distribution, uniform pore network, hydrophilic as well as hydrophobic
  surface functional groups were produced.

 Thus the two natural sources Limonia Acidissima and Myristica Fragrans
  have been successfully utilized for the first time for producing carbon
  materials with desirable properties.




  Reference:


1. B. Viswanathan, P. Indra Neel, T. K. Varadarajan
   A Process for the preparation of Activated Carbon from Botonical Sources
   Indian Patent File No. 376 CHE 2007

								
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