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A study of the reaction between vanadium and hydrogen
IHORG.
HUCL.
CHEM.
LETTER5
Vo|. 2,
pp. 123-127,
1966.
Pergamon Press
Ltd.,
Prln~ed In Greo! Brlfa|n
A STUDY OF THE R E A C T I O N B E T W E E N V A N A D I U M AND H Y D R O G E N * Howard E. Flotow Chemistry
Division,
Argonne National L a b o r a t o r y
Argonne,
Illinois
60439
(Rece;ved|4Aprl11966)
IT HAS B E E N R E P O R T E D by Maeland the c o m p o s i t i o n crystal
VHI.oI
(i) that v a n a d i u m hydride up to
can be prepared by the direct reaction
bar v a n a d i u m metal with H 2 at one atmogphere
Compositions
of VHI.45 and VHI.64 were attained
sure apparatus
with H 2 pressures
of
pressure.
in a high pres-
up to 136 atmospheres
(2).
Impure VHI.77 was claimed to have been made by the electrolysis of VHo.87
in a i0~ H F solution
This letter will report'a
(2). study of the c h a r a c t e r i s t i c s
the reaction between massive v a n a d i u m and H2, V}{I. 7 by the high pressure prepare
compositions
method
the preparation
of powdered
v a n d a d i u m and V H x (x ~ 0.9) with H 2 near i atmosphere The v a n a d i u m metal used for these experiments
product
of a triple-pass
0.63 c m - d i a m e t e r
in ppm were:
25; and Mo,
All m a n i p u l a t i o n s
15.
Approximately contamination,
was in the
rods which were the
O, i00; N, 30;
v a c u u m llne or in a h e l i u m - f i l l e d of the finely divided
pressure.
e l e c t r o n b e a m zone purification.
chief impurities
of
(2) and finally a method to
up to VHI.78 by the reaction
form of p o l y c r y s t a l l i n e
of
C; 65; Fe,
were performed
The i00;
Si,
either on a
dry box to prevent
oxidation
samples.
26 g of v a n a d i u m was cleaned
of surface
a c c u r a t e l y w e i g h e d and put into a stainless
*Based on work performed under the auspices E n e r g y Commission. 123
steel
of the U.S. Atomic
124
VANADIUM*HYDROGEN REACTION
reaction
tube w h i c h was
metal was ture was
initially lowered
then a t t a c h e d
outgassed
lowered
to 10 -6 Torr at 500 ° .
A f t e r 15 min.
of 18 hr.
had stopped.
sample was h e a t e d
The
at 600 T o r t H 2 was
more
t h a n 5 % over a p e r i o d
less as the t e m p e r a t u r e
was
t i o n V H 0 . 6 0 9 was the metal
and the hydride.
in d i a m e t e r visibly
determined
tube and a g a i n thermally
rate was
The r e a c t i o n The V H
rate was
vanadium
The composi-
in w e i g h t
rods were
rods,
even
was transferred
x
by the d i f f e r e n c e The h y d r i d e d
too
in the sample by
but
between
a little
larger
they were not
was put b a c k into the s t a i n l e s s
connected
decomposed
transferred
the v a n a d i u m
to the v a c u u m llne.
to the metal b y h e a t i n g
metal was metal.
indicated increase
as b e f o r e
gave
that h y d r i d e the h y d r o g e n
slow d i f f u s i o n thermodynamic
dry box,
The sample was
formation
and the w e i g h t
VH0.592.
equilibrium.
of
to the r e a c t i o n
This
the
result
cycles w o u l d not
As will be shown below,
of H 2 into m a s s i v e V H x h i n d e r e d
tube
0.2 mg as
Rehydrlding
- decomposition
concentration.
was
The r e a c t i o n
returned
to the v a c u u m line. the c o m p o s i t i o n
reaction
to 500 ° and p u m p i n g
f o u n d to be the same to w i t h i n
and then a t t a c h e d
vanadium
steel
The h y d r i d e
of 2-1/2 hr.
to the h e l i u m - f i l l e d
of o r i g i n a l
vessel
the r e a c t i o n
dry b o x and weighed.
a w a y the e v o l v e d H 2 over a p e r i o d
that
at 465
fissured. The V H 0 . 6 0 9
was
of h y d r o g e n
lowered.
than the o r i g i n a l
time
the r e a c t i o n
of a week.
u n d e r v a c u u m to a h e l i u m - f i l l e d
found to react
to 400 ° , and s slow r e a c t i o n
However,
the c o n c e n t r a t i o n
The t e m p e r a -
was m a i n t a i n e d
At the end of this
observed.
The
at 300 ° , the tempera-
to 200 ° , and the p r e s s u r e
T o r r for a p e r i o d
low to i n c r e a s e
to a v a c u u m line.
to 300 ° , and H 2 at 400 T o r t was
r a p i d l y w i t h the vanadium. ture was
Vol, 2, No. 5
the a t t a i n m e n t
a of
Vol. 2, No. 5
VANADIUM-HYDROGEN
The r o d - s h a p e d was b r o k e n with
into pieces
a hardened
crushing
steel
llne.
the r e a c t i o n reaction
about this
was
H 2 dissociation
because formly
hydrogen
pressure
method was
period.
gain
with
admitted
w~s
that
to
and rapid increased
to
of 30 hr.
maintained
at
The c o m p o s i t i o n
of
this h y d r i d e
pressure
to be sure
was
to the
to be V H 0 . 7 6 1 ± O . O 0 2 .
The
at 25 ° was
is only a p p r o x i m a t e the h y d g r o g e n
in the large hydride
particles,
may not c o r r e s p o n d
converted
also used
closely
in this
then a t t a c h e d
is uni-
and therefore to the average
When
the VHI. 7 was
found
to a source
obtained.
This
experiment
The evidence
by a h i g h
and S c h u m a c h e r A i g portion
(2). of
into a h i g h pressure of p u r i f i e d
high pres-
volumes.
the H 2 pressure
was r e d u c e d
to lose H 2 r a p i d l y
to VHO.9±O. I.
Gibb,
calibrated
to VHI. 7 w i t h
the H 2 pressure
hydrides
laboratory.
and loaded
line w i t h
from VHO.76
higher
by Maeland,
in a m o r t a r
atmospheres.
was
to prepare
was r e p o r t e d
H 2 and to a v a c u u m
result
H 2 was
to 150 ° for a period
associated This
and reloaded
connected
an immediate
the H 2 pressure entire
3 Torr.
attempt
was g r o u n d
t u b ~ w h i c h was
lowered
evacuated,
and by
composition.
This m e t h o d
was
pressure
pressure
The first
VHo.76
this
it is d i f f i c u l t
the o b s e r v e d
sure
to 25°;
distributed
was w e i g h e d
The t e m p e r a t u r e
foumd by weight
to be about
cylinder
in the dry b o x and then
and then l o w e r e d
lowered
sample
steel
sample
the h e l i u m was
700 Torr d u r i n g
found
The crushed
w i t h H 2 at 350 Tort.
and f i n a l l y
than 0.2 cm on an edge by impact
tube at 25 ° and there was
300 ° for 15 min.
125
was very hard and brittle,
rod In a h a r d e n e d
tube
After
which
no larger
in a mortar.
into the r e a c t i o n vacuum
VH0.592,
REACTION
umtll
sample
at ii0
to I atmosphere,
the c o m p o s i t i o n
was r e p e a t e d
indicated
The
that
was
and the same
the e q u i l i b r i u m
126
VANADIUM-HYDROGEN REACTION
H 2 pressure
for VHO.9±O. I is about I atmosphere
that higher hydrides
Vol. 2, No. 5
and suggested
could also be made at lower temperatures
with lower H 2 pressures.
The next two paragraphs
method for the preparation
of VH
give a practical
(x ~ 0.9) which is based upon X
this suggestion. About I g of VHo.76 was ground in an agate mortar until all the particles were much smaller than 10 -3 cm in size as judged by optical examination.
An X-ray pattern of this material
indlo
cated a tetragonal These parameters VH0.76.
structure with ~
O
= 3.03 A and c
agree with those given by Maeland
A weighed portion,
O
= 3.38 A.
(I) for
0.744 g, of this ground VHo.76 was put
into a quartz reaction tube and attached to a vacuum llne which included appropriate Toepler pump.
calibrated volumes,
Hg manometers,
and a
The hydride was decomposed to metal at 450 ° and
from the amount of H 2 which was evolved the composition
of the
original hydride was calculated to be VHO.755. Next,
the maximum volume of H 2 which would react with the
vanadium metal powder at four different mined.
The results are summarized
temperatures
chronologically
was deter-
in Table I.
TABLE I
Temperature (°C)
Cumulative Time (Days)
Hydride Composition
H 2 Pressure (Tort)
-80
VHI.76±O.O I
605
4
-80
VHI.78±O.O I
580
12
-30
VHI.70±O.01
670
13
0
V}{1.45±0.01
751
14
22
VHo.86±O.O I
740
15
vol. 2, No, 5
VANADIUM-HYDROGEN REAC'rION
It can be seen that and p o s s i b l y was
raised
sure were
not
determined
days,
regarded
in 12 days.
ranging
respectively.
results
(3).
approaching
and H 2 pres-
determined
compositions
on the 14th and
at the 0 ° and 22 ° are
the methods
to prepare
and techniques
a series
will be given
of hydrides
neutron
scattering
in a future
publica-
laboratory.
The two other metals namely
the temperature
Similarly,
f r o m VHO. 2 to VHI. 7 for inelastic
tion f r o m this
ble V~ x
period
in # days
values.
to t h i s s t u d y
These
achieved
the c o m p o s i t i o n
The pressures
here were u t i l i z e d
experiments.
table,
this
at 0 ° and 22 ° were
Subsequent
was not
at this temperature.
as e q u i l i b r i u m
described
After
to -30 ° and i day ~ater
and H 2 pressures 15th
at -80 ° e q u i l i b r i u m
127
Nb and Ta,
in the VB group
are known
It is reasonable
to f o r m hydrides
to expect
that
N b H 2 and T a H 2 could be p r e p a r e d
to the one g i v e n
here
of the periodic which
resem-
compositions by a method
similar
for VH1.78. References
I.
A. J. MAELAND,
J. Phys.
2.
A. J. MAELAND,
T. R. P. GIBB,
J. Am. 3.
Chem.
Soc.
T. P. R. GIBB, Cotton,
ed.,
83,
Jr.,
p. 331.
Chem.
3728
Progress
68, Jr.,
2197
(1964).
and D. P. SCHUMACHER,
(1961). in Organic
Interscience
Chemistry,
Publishers,
F. A.
New Y o r k
(1962).
HUCL.
CHEM.
LETTER5
Vo|. 2,
pp. 123-127,
1966.
Pergamon Press
Ltd.,
Prln~ed In Greo! Brlfa|n
A STUDY OF THE R E A C T I O N B E T W E E N V A N A D I U M AND H Y D R O G E N * Howard E. Flotow Chemistry
Division,
Argonne National L a b o r a t o r y
Argonne,
Illinois
60439
(Rece;ved|4Aprl11966)
IT HAS B E E N R E P O R T E D by Maeland the c o m p o s i t i o n crystal
VHI.oI
(i) that v a n a d i u m hydride up to
can be prepared by the direct reaction
bar v a n a d i u m metal with H 2 at one atmogphere
Compositions
of VHI.45 and VHI.64 were attained
sure apparatus
with H 2 pressures
of
pressure.
in a high pres-
up to 136 atmospheres
(2).
Impure VHI.77 was claimed to have been made by the electrolysis of VHo.87
in a i0~ H F solution
This letter will report'a
(2). study of the c h a r a c t e r i s t i c s
the reaction between massive v a n a d i u m and H2, V}{I. 7 by the high pressure prepare
compositions
method
the preparation
of powdered
v a n d a d i u m and V H x (x ~ 0.9) with H 2 near i atmosphere The v a n a d i u m metal used for these experiments
product
of a triple-pass
0.63 c m - d i a m e t e r
in ppm were:
25; and Mo,
All m a n i p u l a t i o n s
15.
Approximately contamination,
was in the
rods which were the
O, i00; N, 30;
v a c u u m llne or in a h e l i u m - f i l l e d of the finely divided
pressure.
e l e c t r o n b e a m zone purification.
chief impurities
of
(2) and finally a method to
up to VHI.78 by the reaction
form of p o l y c r y s t a l l i n e
of
C; 65; Fe,
were performed
The i00;
Si,
either on a
dry box to prevent
oxidation
samples.
26 g of v a n a d i u m was cleaned
of surface
a c c u r a t e l y w e i g h e d and put into a stainless
*Based on work performed under the auspices E n e r g y Commission. 123
steel
of the U.S. Atomic
124
VANADIUM*HYDROGEN REACTION
reaction
tube w h i c h was
metal was ture was
initially lowered
then a t t a c h e d
outgassed
lowered
to 10 -6 Torr at 500 ° .
A f t e r 15 min.
of 18 hr.
had stopped.
sample was h e a t e d
The
at 600 T o r t H 2 was
more
t h a n 5 % over a p e r i o d
less as the t e m p e r a t u r e
was
t i o n V H 0 . 6 0 9 was the metal
and the hydride.
in d i a m e t e r visibly
determined
tube and a g a i n thermally
rate was
The r e a c t i o n The V H
rate was
vanadium
The composi-
in w e i g h t
rods were
rods,
even
was transferred
x
by the d i f f e r e n c e The h y d r i d e d
too
in the sample by
but
between
a little
larger
they were not
was put b a c k into the s t a i n l e s s
connected
decomposed
transferred
the v a n a d i u m
to the v a c u u m llne.
to the metal b y h e a t i n g
metal was metal.
indicated increase
as b e f o r e
gave
that h y d r i d e the h y d r o g e n
slow d i f f u s i o n thermodynamic
dry box,
The sample was
formation
and the w e i g h t
VH0.592.
equilibrium.
of
to the r e a c t i o n
This
the
result
cycles w o u l d not
As will be shown below,
of H 2 into m a s s i v e V H x h i n d e r e d
tube
0.2 mg as
Rehydrlding
- decomposition
concentration.
was
The r e a c t i o n
returned
to the v a c u u m line. the c o m p o s i t i o n
reaction
to 500 ° and p u m p i n g
f o u n d to be the same to w i t h i n
and then a t t a c h e d
vanadium
steel
The h y d r i d e
of 2-1/2 hr.
to the h e l i u m - f i l l e d
of o r i g i n a l
vessel
the r e a c t i o n
dry b o x and weighed.
a w a y the e v o l v e d H 2 over a p e r i o d
that
at 465
fissured. The V H 0 . 6 0 9
was
of h y d r o g e n
lowered.
than the o r i g i n a l
time
the r e a c t i o n
of a week.
u n d e r v a c u u m to a h e l i u m - f i l l e d
found to react
to 400 ° , and s slow r e a c t i o n
However,
the c o n c e n t r a t i o n
The t e m p e r a -
was m a i n t a i n e d
At the end of this
observed.
The
at 300 ° , the tempera-
to 200 ° , and the p r e s s u r e
T o r r for a p e r i o d
low to i n c r e a s e
to a v a c u u m line.
to 300 ° , and H 2 at 400 T o r t was
r a p i d l y w i t h the vanadium. ture was
Vol, 2, No. 5
the a t t a i n m e n t
a of
Vol. 2, No. 5
VANADIUM-HYDROGEN
The r o d - s h a p e d was b r o k e n with
into pieces
a hardened
crushing
steel
llne.
the r e a c t i o n reaction
about this
was
H 2 dissociation
because formly
hydrogen
pressure
method was
period.
gain
with
admitted
w~s
that
to
and rapid increased
to
of 30 hr.
maintained
at
The c o m p o s i t i o n
of
this h y d r i d e
pressure
to be sure
was
to the
to be V H 0 . 7 6 1 ± O . O 0 2 .
The
at 25 ° was
is only a p p r o x i m a t e the h y d g r o g e n
in the large hydride
particles,
may not c o r r e s p o n d
converted
also used
closely
in this
then a t t a c h e d
is uni-
and therefore to the average
When
the VHI. 7 was
found
to a source
obtained.
This
experiment
The evidence
by a h i g h
and S c h u m a c h e r A i g portion
(2). of
into a h i g h pressure of p u r i f i e d
high pres-
volumes.
the H 2 pressure
was r e d u c e d
to lose H 2 r a p i d l y
to VHO.9±O. I.
Gibb,
calibrated
to VHI. 7 w i t h
the H 2 pressure
hydrides
laboratory.
and loaded
line w i t h
from VHO.76
higher
by Maeland,
in a m o r t a r
atmospheres.
was
to prepare
was r e p o r t e d
H 2 and to a v a c u u m
result
H 2 was
to 150 ° for a period
associated This
and reloaded
connected
an immediate
the H 2 pressure entire
3 Torr.
attempt
was g r o u n d
t u b ~ w h i c h was
lowered
evacuated,
and by
composition.
This m e t h o d
was
pressure
pressure
The first
VHo.76
this
it is d i f f i c u l t
the o b s e r v e d
sure
to 25°;
distributed
was w e i g h e d
The t e m p e r a t u r e
foumd by weight
to be about
cylinder
in the dry b o x and then
and then l o w e r e d
lowered
sample
steel
sample
the h e l i u m was
700 Torr d u r i n g
found
The crushed
w i t h H 2 at 350 Tort.
and f i n a l l y
than 0.2 cm on an edge by impact
tube at 25 ° and there was
300 ° for 15 min.
125
was very hard and brittle,
rod In a h a r d e n e d
tube
After
which
no larger
in a mortar.
into the r e a c t i o n vacuum
VH0.592,
REACTION
umtll
sample
at ii0
to I atmosphere,
the c o m p o s i t i o n
was r e p e a t e d
indicated
The
that
was
and the same
the e q u i l i b r i u m
126
VANADIUM-HYDROGEN REACTION
H 2 pressure
for VHO.9±O. I is about I atmosphere
that higher hydrides
Vol. 2, No. 5
and suggested
could also be made at lower temperatures
with lower H 2 pressures.
The next two paragraphs
method for the preparation
of VH
give a practical
(x ~ 0.9) which is based upon X
this suggestion. About I g of VHo.76 was ground in an agate mortar until all the particles were much smaller than 10 -3 cm in size as judged by optical examination.
An X-ray pattern of this material
indlo
cated a tetragonal These parameters VH0.76.
structure with ~
O
= 3.03 A and c
agree with those given by Maeland
A weighed portion,
O
= 3.38 A.
(I) for
0.744 g, of this ground VHo.76 was put
into a quartz reaction tube and attached to a vacuum llne which included appropriate Toepler pump.
calibrated volumes,
Hg manometers,
and a
The hydride was decomposed to metal at 450 ° and
from the amount of H 2 which was evolved the composition
of the
original hydride was calculated to be VHO.755. Next,
the maximum volume of H 2 which would react with the
vanadium metal powder at four different mined.
The results are summarized
temperatures
chronologically
was deter-
in Table I.
TABLE I
Temperature (°C)
Cumulative Time (Days)
Hydride Composition
H 2 Pressure (Tort)
-80
VHI.76±O.O I
605
4
-80
VHI.78±O.O I
580
12
-30
VHI.70±O.01
670
13
0
V}{1.45±0.01
751
14
22
VHo.86±O.O I
740
15
vol. 2, No, 5
VANADIUM-HYDROGEN REAC'rION
It can be seen that and p o s s i b l y was
raised
sure were
not
determined
days,
regarded
in 12 days.
ranging
respectively.
results
(3).
approaching
and H 2 pres-
determined
compositions
on the 14th and
at the 0 ° and 22 ° are
the methods
to prepare
and techniques
a series
will be given
of hydrides
neutron
scattering
in a future
publica-
laboratory.
The two other metals namely
the temperature
Similarly,
f r o m VHO. 2 to VHI. 7 for inelastic
tion f r o m this
ble V~ x
period
in # days
values.
to t h i s s t u d y
These
achieved
the c o m p o s i t i o n
The pressures
here were u t i l i z e d
experiments.
table,
this
at 0 ° and 22 ° were
Subsequent
was not
at this temperature.
as e q u i l i b r i u m
described
After
to -30 ° and i day ~ater
and H 2 pressures 15th
at -80 ° e q u i l i b r i u m
127
Nb and Ta,
in the VB group
are known
It is reasonable
to f o r m hydrides
to expect
that
N b H 2 and T a H 2 could be p r e p a r e d
to the one g i v e n
here
of the periodic which
resem-
compositions by a method
similar
for VH1.78. References
I.
A. J. MAELAND,
J. Phys.
2.
A. J. MAELAND,
T. R. P. GIBB,
J. Am. 3.
Chem.
Soc.
T. P. R. GIBB, Cotton,
ed.,
83,
Jr.,
p. 331.
Chem.
3728
Progress
68, Jr.,
2197
(1964).
and D. P. SCHUMACHER,
(1961). in Organic
Interscience
Chemistry,
Publishers,
F. A.
New Y o r k
(1962).