This document summarizes a study on the kinetics of sodium borohydride hydrolysis using cobalt chloride as a catalyst. The study was conducted by Arshdeep Kaur under the guidance of Pramod K. Bajpai and Dr. D. Gangacharyulu at Thapar University in Patiala, India. The study examined the effects of temperature, sodium borohydride concentration, sodium hydroxide concentration, and cobalt chloride concentration on the hydrolysis reaction rate. Kinetic parameters including the reaction order and rate constants were determined. Hydrogen gas was qualitatively and quantitatively analyzed. Residual products were examined using scanning electron microscopy.

1. KINETICS OF HYDROLYSIS OF SODIUM BOROHYDRIDE USING
COBALT CHLORIDE CATALYST
By
Arshdeep Kaur
(Research scholar)
Under guidance of
Pramod K. Bajpai
(Distinguished Professor)
Copyright 2013-2014
Dr. D. Gangacharyulu
(Professor)
DEPARTMENT OF CHEMICAL ENGINEERING
THAPAR UNIVERSITY
PATIALA-147004, INDIA.
December 2013
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2. Outline of presentation
 Introduction
 Literature Review
 Experimental
 Results and Discussions
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 Conclusion
 Acknowledgements
 References
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4. ENERGY FACTS
 Fossil fuels are depleted at a rate
that is 100,000 times faster than
they are formed.
 On average, 16 million tons of
carbon dioxide is emitted into the
atmosphere every 24 hours by
human use worldwide.
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 Coal is the single biggest air
polluter and burning coal causes
smog, soot, acid rain, global
warming, and toxic air emission.
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Transition To Hydrogen Energy
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6. HYDROGEN FACTS
Hydrogen is considered as clean
energy source and long term
solution
towards
sustainable
energy future.

1 kg of Hydrogen has same energy
than 2.8 kg of gasoline, therefore
hydrogen stores 2.8 times more
energy than gasoline.

Effective storage of hydrogen is
one of the key elements of
hydrogen economy.
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
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8. Lit. Rev....
Physical storage in tanks
Compressed Hydrogen Tanks
Cyro-Compressed Hydrogen Storage
Compressed Gas
Storage in high pressurised tanks up to 700 Hydrogen cooled to 253oC and pressurised
bars.
to 6 - 350 bars in insulated tanks.
High energy and cost requirements for Cost factors for cooling and pressurising
pressurising gas in tanks .
hydrogen gas in tanks.
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Cryogenic Liquid

9. Lit. Rev....
Solid state hydrogen storage
(A) Adsorption, hydrogen attaches to surface of molecules as hydrogen molecules.
Larger quantities of hydrogen in smaller volumes at low pressures and at
temperature nearly equal to room temperature can be stored.
(C) & (D) Hydrogen is strongly bound within molecular structures, as chemical
compounds containing hydrogen atoms.
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(B) Absorption, hydrogen molecules dissociate into hydrogen atoms that are
incorporated into the solid lattice framework .

10. Lit. Rev....
Storing hydrogen in chemical hydrides
0.126
H2 Specific mass
(kg H / kg)
0.25
H2 Density
(kg H2 / liter)
0.122
NaH + H2O → NaOH + H2
0.042
0.083
0.106
CaH2 + 2H2 O → Ca(OH)2 + 2H2
0.048
0.095
0.121
MgH2 → Mg + H2
0.076
0.076
0.110
LiAlH 4 + H2 O → LiOH + Al + 2.5 H2
0.105
0.132
0.121
TiH2 → Ti + H2
0.040
0.040
0.152
0.184
0.367
0.235
0.105
0.211
0.226
0.077
0.077
LiBH 4 + H2O →
NaBH4 + 2H2O→
LiOH + HBO2 + 4H2
NaBO2 + 4H2
Fraction H
Millennium Cell 35% Solution
NaBH4 + 4H2 O → NaBO2 + 4H2+ 2H2O
Source: M.Klanchar et al. [1]
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Hydride reactions and hydrogen storage
properties
LiH + H2O → LiOH + H2

11. Lit. Rev....
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Comparison of hydrogen storage properties
Source: M. Klanchar et al. [1]
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12. Lit. Rev....
Sodium borohydride hydrogen storage
Hydrolysis Reaction
NaBH4 + 2H2O
NaBO2 + 4H2
 Sodium borohydride reacting with water to produce hydrogen.
 Generated H2 is high purity (no traces of CO and S).
 It is the least expensive metal hydride commercially available, and it is
safe to use, handle and store.
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 No side reactions or no volatile by products are formed.

13. Lit. Rev....
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Comparison of chemical hydrides
Source: Y. Wu et al. [2]
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14. Lit. Rev....
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Volumetric storage efficiency
Source: Y. Wu et al. [2]
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15. Lit. Rev....
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Gravimetric storage efficiency
Source: Y. Wu et al. [2]
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16. Lit. Rev....
CoCl2 + 2NaBH4 + 3H2O

25/4H2 + 1/2Co2B + 2NaCl
Cl- is neoclophilic in nature, Co2+ is electrophlic in nature, which increase its reactivity
toward BH- ions . Therefore this explains better reactivity of CoCl2 for NaBH4.
Source:O.Akdim et al. [3]
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Cobalt chloride as a catalyst for hydrolysis reaction

17. Lit. Rev......
S. No
Hydrogen storage
modes
Observations
References
Hydrogen storage
with chemical
hydrides
Hydrogen fraction found best in
LiBH4(0.184), LiH(0.126), LiAlH4
(0.105), NaBH 4 (0.105)
Klancher et
al., 2003
2.
Various modes of
hydrogen storage
Energy density increases from
compressed hydrogen storage
<cryo- compressed hydrogen
storage<adsorption
<absorption<chemical hydrides
Cleveland,
2008
3.
Hydrogen generation
from chemical
hydrides
Hydrogen storage system
technologies , role of water in
hydrolysis reaction are discussed
MarreroAlfonso et
al., 2009
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1.

18. Lit. Rev....
S.No
Catalyst
Observations
References
Rate kinetics studied, hydrolysis reaction
Shang ,
with sodium borohydride was found to be
2006
is 1st order.
2.
Co-B
Hydrogen generation from NaBH4 using Jeong et al.,
Co- B catalyst.
2005
Co-B
First order kinetics at low NaBH4
Dai et
concentrations and zero order at high
al.,2008
NaBH4 concentrations.
4.
Cobalt (II) salts
CoCl2 showed best performance in
Akdim et
hydrogen
generation
followed
by
al., 2009
Co(CH3OO)2>CoSO4>CoF2
5.
Acid treated
CoCl2/Al2O3
Best performance was observed by HCl
Demirci, et
and CH3COOH followed by citric acid>
al.,2009
oxalic acid>sulphuric acid.
3.
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1.
Carbon supported
ruthenium catalyst

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20. Chemicals
 Sodium borohydride (NaBH4) powder with molecular weight of
37.8 g/mol and purity of 97%.
 NaOH pellets having molecular weight 39.9 g/mol and purity of
97% .
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 Cobalt chloride (CoCl2) salt powder in hexa-hydrate
form, having molecular weight 237.93 g/mol with a purity of
98%.

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Schematic diagram of experimental setup
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Experimental Setup
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24. Factors effecting the rate of hydrolysis
reaction
Temperature
According to the hydrolysis reaction at concentration of NaBH4 equal to 0.55
g and CoCl2 concentration 0.06 g, rate of hydrogen generation increases with
increase in temperature.
1200
1000
800
30 C
600
35 C
40 C
400
45 C
50 C
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rate of hydrogen generation (ml/min)
1.
200
0
0
2
4
6
8
10
12
Time(min)
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25. Continued…
Rate constant with temperature can be expressed by Arrhenius equation
k
Ae
E
RT
The values of E and A were estimated by substituting the k values at 45 o
C and 63 C, where E = 37.931 kJ/mol and A = 12.54 Χ 108 sec-1.
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E is the apparent activation energy, A is the pre exponential factor ,R is
the universal gas constant, and T is the reaction temperature, K.

26. Continued…
2.
The Sodium Hydroxide (NaOH) Concentration
 NaBH4 undergoes self hydrolysis and to suppress the self hydrolysis
sodium hydroxide (NaOH)is added.
 The excess amount of NaOH decreases the hydrogen yield.
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 Experimental results shows hydrogen generation rate decreases with
increase NaOH concentration and temperature, at constant NaBH4
concentration and CoCl2 concentration.
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27. Continued…
The NaBH4 Concentration: The hydrogen generation rate increases with increase
NaBH4 concentration with constant NaOH percentage.
Hydrogen
Molality of
Temperature
CoCl2 (g)
NaOH (%)
generation rate
NaBH4(mol/kg)
(oC)
(ml/min)
1.19
0.05
45
0
300
1.45
0.06
45
0
480
1.71
0.07
45
0
520
1.98
0.08
45
0
600
1.19
0.05
55
0
320
1.45
0.06
55
0
420
1.71
0.07
55
0
480
1.98
0.08
55
0
560
1.19
0.05
63
0
340
1.45
0.06
63
0
480
1.71
0.07
63
0
560
1.98
0.08
63
0
620
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3.

28. Rate Kinetics
 Rate increase with the increase of NaBH4 concentration at a fixed temperature
and NaOH concentration.
rH2
km NaBH4
where rH2 is the rate of hydrogen generation in milliliters per minute, mNaBH4 is
the molality of NaBH4, and α is the apparent reaction order, k is proportionality
constant.
rH 2
1
1
k 1 w NaOH
where , w NaOH is the concentration of NaOH in weight percent and k1 is a
proportional constant.
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 Hydrogen generation rate decreased with the increase of NaOH concentration
at a fixed NaBH4 concentration and temperature.

29. Continued…
Rate law of hydrogen generation from a basic NaBH4 solution can be
expressed using equation ,
rH 2
km NaBH4
1 k 1 w NaOH
Calculated order of the reaction (α) w.r.t NaBH4 concentration equals 1
with experimental error 0.2 and is shown in tabulated form on next slide.
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The parameters k/ (1 + k1wNaOH) and α can then be determined by
regressing the maximum hydrogen generation rate and the initial NaBH4
concentration.

30. Parameters calculated at various temperature and
NaOH concentrations
NaOH concentration
(%)
k/ (1 + k1WNaOH)
α (Reaction Order)
25
0
133.62
1.2
35
0
226.16
0.94
45
0
271.10
1.2
55
0
283.68
0.96
63
0
377.09
1
25
1
214.32
1
35
1
345.50
0.95
45
1
438.12
0.98
55
1
676.88
1
63
1
871.15
1
35
3
241.65
1.2
45
3
375.21
1.2
55
3
566.79
1.2
63
3
464.05
1
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Temperature ( C)
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31. Calculation of the rate constants k and k1
1
rH 2
1
m NaBH4
k
k 1 w NaOH
k m NaBH4
 Plot of 1/rH2 versus w NaOH /mNaBH4 gives a straight-line graph.
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 The intercept on the y axis is 1/kmNaBH4 and the slope is
k1/k, from which both k and k1 may be determined.
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Calculations of the rate constants k and k1
Regression at 63oC and 1.45g of NaBH4
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33. Parameters calculated at various temperatures and
NaBH4 concentrations
Temperature (o C)
k (min-1)
k1 (min-1)
1.19
35
192.30
0.02
1.19
45
555.55
0.13
1.19
63
1666.66
0.7
1.45
45
555.55
0.14
1.45
63
2000
0.8
1.71
35
740.74
0.4
1.71
45
769.23
0.6
1.71
63
2500
0.9
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Molality (mol/kg)
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34. Hydrogen Gas Qualitative Analysis by Pop Test
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Light a wooden splint and then hold it to area that contain hydrogen, a
squeaky pop is observed if hydrogen is present.
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35. Hydrogen gas quantitative analysis by gas
chromatography
AIMIL-NUCON Gas Chromatograph
The Test shows the Purity of 85% with rest being nitrogen from air as per
recovery basis from the sample.
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A quantitative analysis test was conducted for hydrogen gas by Gas
Chromatography, from Sophisticated Analytical Instrument Laboratory, Thapar
University Patiala.

36. Residual analysis
Scanning Electron Microscope (SEM): SEM was performed for the
residual
substance
from
Sophisticated
Analytical
Instrument
Laboratory, Thapar University Patiala.
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1.
Residue analysis by SEM
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37. Continued…
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2. Energy Dispersive Electron Microscopy (EDAX): EDAX was performed
in Sophisticated Analytical Instrument Laboratory, Thapar University
Patiala. It shows the presence of Sodium (Na), Cobalt (Co), Chlorine
(Cl), Oxygen (O).
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38. CONCLUSIONS
 Hydrolysis reaction of sodium borohydride with cobalt chloride as catalyst is a
first order reaction.
 Hydrogen generation rate increases with increase in temperature, sodium
borohydride (NaBH4) concentration and decreases with sodium hydroxide
(NaOH) concentration.
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 The rate constant ‘k’ with respect to sodium borohydride increased significantly
from 555.50 min-1 to 1666.40 min-1 when the temperature increased from 45 to
63 C. However, rate constant ‘k1’ with respect to sodium hydroxide did not
change significantly with NaBH4 concentration and temperature.
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39. Continued…
 The gas chromatography analysis indicates, the hydrogen gas purity is
85% and rest is nitrogen. The tendency of sodium borohydride to store
and release hydrogen is more effective and favorable.
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 The hydrogen generation rates are observed to be higher from hydrolysis
studies of alumina nanoparticles - NaBH4 - CoCl2 system as compared to
NaBH4 - CoCl2 systems.
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40. References
1. Shang, Y. and Chen, R., Semiempirical Hydrogen Generation Model Using Concentrated
Sodium Borohydride Solution, J. Energy & Fuels, Vol. 20, No. 5, 2006, pp. 2149-2154.
2. Ying, W., Hydrogen Storage via Sodium Borohydride, Presented by Stanford
University, 2003.
3. Liu, R.S.; Lai, H.C.; Bagkar, N.C.; Kuo, H.T.; Chen, H.N.; Lee, J.F.; Chung, H.J.;
Chang, S.M.; and Weng, B.J., Investigation on Mechanism of Catalysis by Pt-LiCoO2
for Hydrolysis of Sodium Borohydride Using X-ray Absorption, J. Phys. Chem. B , Vol.
112, No. 16,2008 pp. 4870-4875.
5. Shang, Y. and Chen, R., Hydrogen Storage via the Hydrolysis of NaBH4 Basic
Solution, Optimization of NaBH4 Concentration, Energy & Fuels, Vol. 20, No.
5, 2006, pp.2142-2148.
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4. Marrero-Alfonso, E.Y.; Beaird, A.M.; Davis, T.A.; Matthews, M.A., Hydrogen
Generation from Chemical Hydrides, Ind. Eng. Chem. Res., Vol.48, No.8,2009 pp.37033712.

41. Continued...
6. Cleveland, C.J., Hydrogen storage, Encyclopaedia of Earth, 2008.
7. Klanchar, M.; Hughes, T.G.; Gruber, P., Attaining DOE Hydrogen storage Goals with
Chemical Hydrides, Applied Research Laboratory, The Pennsylvania State
University, 2003.
8. Klanchar, M.; Lloyd, C.L.; Compact Hydrogen Generating Systems Based on
Chemical Sources for Low and High Power Applications, Proceedings of the 39th
Power Sources Conference, 2000, pp. 188-191.
10. Wu, Y., Process for the Regeneration of Sodium Borate to Sodium Borohydride for Use
as a Hydrogen Storage Source, New FY 2004 Project, U. S. Department of
Energy, Office of Energy Efficiency and Renewable Energy, FY 2003 Progress Report
for Hydrogen, Fuel Cells, and Infrastructure Technologies Program, October 2003.
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9. McClaine, A.W., Chemical Hydride Slurry for Hydrogen Production and Storage, New
FY 2004 Project, U. S. Department of Energy, Office of Energy Efficiency and
Renewable Energy, FY 2003 Progress Report for Hydrogen, Fuel Cells, and
Infrastructure Technologies Program, October 2003.

42. Continued...
11. Hydrogen, Fuel Cells & Infrastructure Technologies Program Multi- Year Research, Development
and Demonstration Plan, Department of Energy, Washington D.C., 2005.
12. Zuttel, A., Hydrogen Storage Methods, Springer-Verlag, Vol. 91, No. 4, 2004, pp. 157–172.
13. Aggrawal, R.; Offutt, M.R.; Ramage, M.P., Hydrogen Economy and Opportunity for Chemical
Engineers, AIChE journal,Vol.51, No. 6, 2005, pp. 1582–1589.
14. Kennedy, D., The Hydrogen Solution Science, Journal of American Chemical Society, Vol.
305, No.5686, 2004, pp.917.
15. Ritter, J.; Ebner, A.; Wang, A.D.; Zidan, J., Implementing a Hydrogen Economy, Journal of
Physical Chemistry, Vol.6, No. 9, 2003, pp.18–23.
16. Othmer, K., Encyclopedia of Chemical Technology, 4th ed., Vol. 13, pp. 606-629, New York 1991.
pp.
18. Shang, Y. and Chen, R., Hydrogen Storage via the Hydrolysis of NaBH4 Basic Solution:
Optimization of NaBH4 Concentration, Energy &Fuels, Vol.20, No.5, 2006, pp. 2142–2148.
11. www.eia.gov
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17. James, B.D.; Wallbridge, G.H., Metal Tetrahydroborates, Prog. Inorg. Chem, Vol. 11, 1970,
99–231.

43. Acknowledgements
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The authors gratefully acknowledge the support provided
by management of Thapar University, Patiala and Thapar
Centre for Industrial Research and Development, Patiala,
India, for providing the necessary facilities to carry out
this research work.
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