Nghiên cứu phản ứng hydrogen hóa CO bằng các hệ xúc tác lưỡng kim loại ni cu, co cu phân tán trên các chất mang than hoạt tính, mgo, al2o3 theo phương pháp phiếm hàm mật độ tt tiếng anh

MINISTRY OF EDUCATION AND TRAINING
HANOI UNIVERSITY OF EDUCATION

NGUYEN BINH LONG

RESEARCH THE HYDROGENATION OF CO
BY BIMETALLIC CATALYST Ni-Cu, Co-Cu
DISPERSED ON CARRIERS OF ACTIVATED
CARBON, MgO, Al2O3 ACCORDING TO
DENSITY FUNCTIONAL THEORY METHOD

Specialization: Theoretical and Physical Chemistry
Code: 9.44.01.19

SUMMARY OF CHEMICAL PhD THESIS

HA NOI – 2020
1


The thesis was completed at: Department of Chemistry - Hanoi
University of Education

Scientific Instructors:
1. Assoc. Prof. Dr. NGUYEN NGOC HA
2. Prof. Dr. JOHN Z. WEN

Review 1: Prof. Dr. Lam Ngoc Thiem - Hanoi University of
Science, VNU.
Review 2: Assoc. Prof. Dr. Vu Anh Tuan - Institute of
Chemistry.

Review 3: Assoc. Prof. Dr. Le Van Khu – Hanoi National
University of Education.

The thesis will be presented to the Board of thesis review at Hanoi
University of Education on .....h..... day..... month ... year...

The thesis can be found at: National Library, Hanoi or the library of
Hanoi National University of Education

2


LIST OF WORKS PUBLISHED BY AUTHOR
1. Nguyen Ngoc Ha, Nguyen Thi Thu Ha, Nguyen Binh Long, Le
Minh Cam. Conversion of Carbon Monoxide into Methanol on AluminaSupported Cobalt Catalyst: Role of the Support and Reaction Mechanism - A
Theoretical Study. 2019, Catalysts, 9(1):6. DOI: 10.3390/catal9010006 (IF =
3.444, Q2).
2. Nguyễn Bình Long, Nguyễn Thị Thu Hà, Lê Minh Cầm, Nguyễn
Ngọc Hà. Nghiên cứu lí thuyết khả năng hấp phụ CO và H2 Của hệ xúc tác
lưỡng kim loại Ni-Cu trên chất mang MgO(200) bằng phương pháp phiếm
hàm mật độ. Tạp chí hóa học, 2018, 56, 6e2, 189-193.
3. Nguyễn Bình Long, Nguyễn Thị Thu Hà, Lê Minh Cầm, Phùng Thị
Lan, Nguyễn Ngọc Hà. Nghiên cứu lí thuyết phản ứng hydrogen hóa CO trên
hệ xúc tác lưỡng kim loại Ni 2Cu2 trên chất mang MgO(200) bằng phương pháp
phiếm hàm mật độ. Tạp chí hóa học, 2019, 57, 2e1,2, 108-114.
4. Nguyễn Bình Long, Nguyễn Thị Thu Hà, Phùng Thị Lan, Lê Minh
Cầm, Nguyễn Ngọc Hà. Nghiên cứu lí thuyết phản ứng hydro hóa CO trên hệ
xúc tác lưỡng kim loại Co2Cu2 trên chất mang MgO(200) bằng phương pháp
phiếm hàm mật độ. Phần 1: Giai đoạn hấp phụ và hoạt hóa. Tạp chí khoa học,
Trường ĐHQG Hà Nội, Vol. 36 No 1 (2020) 81-89.

5. Nguyễn Bình Long, Nguyễn Thị Thu Hà, Lê Minh Cầm, Nguyễn Ngọc
Hà. Nghiên cứu lí thuyết phản ứng hydro hóa CO trên hệ xúc tác lưỡng kim
loại Co2Cu2 trên chất mang MgO(200) bằng phương pháp phiềm hàm mật độ.
Phần 2: Cơ chế phản ứng. Tạp chí khoa học, Trường ĐHQG Hà Nội
(accepted).

3


INTRODUCTION
1. The reason for choosing topic
With the development of industry, the demand for energy has become
increasingly urgent. Fossil fuels such as oil and coal with limited reserves have
been fully exploited, leading to depletion. In addition, the burning of these
fuels creates large amounts of CO 2, CO.... causing environmental pollution,
seriously affecting human health. Therefore, the search for alternative energy
sources is an urgent issue on a global scale.
Although there have been many empirical studies on syngas metabolism
(CO and H2) on single transition metal catalysts or with additional promoter, so
far, syngas reaction mechanism on multi-component catalyst systems
(metal/promoter/carrier) is still a problem for scientists. From a theoretical
research perspective, there are also many studies on syngas metabolism on
single catalyst systems such as Ni, Co, Cu, etc. However, the number of
studies on syngas reaction above multi-component catalyst systems, such as
bimetal metal catalyst carriers on carriers, are very limited. While the research
results for these systems, if any, will provide useful information clarifying the
role of metal centers, the role of carriers, ... thereby elucidating the antiapplication. Theoretical studies of the syngas transformation reaction on
bimetallic catalyst systems can be facilitated by computational chemical
methods. Thereby, information about geometric structure, electron structure,
energy, properties, the role of substances, intermediate products, transition

state and interactions can be obtained.
Therefore, we conduct research on the topic: “Research the hydrogenation
of CO by bimetallic catalyst Ni-Cu, Co-Cu dispersed on carriers of activated
carbon, MgO, Al2O3 according to density functional theory method”.
2. Research purpose
Using computational chemistry methods to study the mechanism of
hydrogenation CO on the transition metal catalyst systems of Ni, Cu, Co,
bimetallic catalysts NiCu, CoCu and catalytic systems bearing cluster on oxide
carriers: MgO, Al2O3 and activated carbon (AC); compare and clarify the role
of catalyst centers in single or bimetallic catalyst systems; clarifies the role of
carriers (MgO, Al2O3 and AC) in the hydrogenation of CO.
3. Research tasks
a) Researching documents, developing an overview and evaluation of the
following issues:
- Theoretical basis of quantum chemical problems; thermodynamics and
related kinetics; Chemical calculation methods used in the thesis (DFT, CINEB, MD and Monter Carlo simulations).
- The situation of studying syngas metabolism reaction on catalysts in the
country and in the world; outstanding and unresolved issues.

4


b) Carry out studies to calculate the hydrogenation reaction mechanism of
CO on catalyst systems: Cluster of Ni, Cu, Co, NiCu, CoCu and catalyst
systems on MgO, Al2O3 and AC carriers:
- Modeling and optimizing structures of CO, H 2, Ni, Cu, Co, NiCu, CoCu,
MgO, Al2O3, AC, Ni/MgO (AC), Cu/cluster systems MgO (AC), NiCu/MgO
(AC); Cu/Al2O3, Co/Al2O3, CuCo/Al2O3.
- Research, predict adsorption sites, priority responses.
- Study the adsorption and activation process of CO and H 2 on the above

catalyst systems: calculation of adsorption energy values, density distribution,
analysis of changes in structural parameters (if any), clarify the nature of the
adsorption process (physical or chemical);
- Study the CO conversion reactions on the catalyst to create alcohol
products (methanol, ethanol) and other organic products (methane,
formaldehyde, ...): propose and calculate energy parameters for reaction lines,
identification of transition states, intermediate products in reaction lines. From
there, build potential potential surface, evaluate and select priority reaction
lines.
- Evaluate and compare the performance and selectivity of the catalyst
systems.
4. Scope and object of the study
- Substances involved initially: CO, H2.
- Possible products of syngas metabolism: methane, methanol, ethanol,
formaldehyde, formic acid ...
- Transitional metal clusters: Ni4, Cu4, Co4, Ni2Cu2, Cu2Co2.
- Carriers: metal oxides: Al2O3, MgO and activated carbon (AC).
5. Scientific and practical significance of the thesis
* Scientific significance:
- Using quantum chemical calculation methods, the results of the thesis
provide a complete picture at the molecular level of the processes and stages
occurring in the hydrogenation of CO on the Metal transition systems: Ni, Cu,
Co and bimetallic NiCu, CoCu, contributing to elucidate syngas metabolic
reaction; clarifies and explains the role of metal centers, the role of the
substance that gives the selectivity and the product of the reaction. The results
obtained are useful references for scientists, graduate students, students in the
field of catalysis - adsorption, chemical calculation.
* Practical significance:
- The results of the thesis are the basis for designing and constructing new
catalysts (bimetallic) with high efficiency and selectivity for syngas

metabolism to create high-chain alcohol, thereby contributing to the
development of developing technology to transform syngas mixture into useful

5


organic products, simultaneously solving two economic and environmental
issues.

6. New points of the thesis
- Studied the stages of adsorption and activation of CO and H 2, and the
mechanism of hydrogenation of CO to create different products (methanol,
methane, high alcohol), constructing potential surfaces of the reaction. Applied
on 7 catalyst systems: NiCu/AC, Ni2Cu2/AC, Ni2Cu2/MgO, Co2Cu2/MgO,
Co4/Al2O3, Cu4/Al2O3 and Co2Cu2/Al2O3.
- Calculation results for the hydrogenation CO on catalyst system show that
bimetallic sites effectively reduce the activation energy of CO insertion and
hydrogenation reactions to CH3*, resulting in the formation of oxygencontaining C2 products (e.g. ethanol) as main products on these positions. All
the catalysts are all potential catalysts.
- For the reaction to create ethanol, identified important intermediates that
determine ethanol selection are CH3O*, CH2OH*, CH3* and CH3CO*. The
hydrogenation and dissociation capacity of CH3O*, CH2OH* intermediate
particles directly affects methanol selection. The selectivity of ethanol also
increases with increasing surface area of the bimetallic sites on the catalyst by
weakening CO adsorption and preventing methaneization.
- The most potential and favorable catalyst for ethanol synthesis is
proposed as Co2Cu2/Al2O3 system. Most reactions on Co2Cu2/Al2O3 catalysts
have small Ea and negative ∆E. The role of Al2O3 in the hydrogenation of CO
has been shown.
7. The layout of the thesis

Introduction: Introducing the reasons for choosing the topic, the purpose
and scope of the research, the new points of the thesis, the scientific and
practical significance of the thesis.
Content: 03 chapters
Chapter 1: Introduce the theoretical basis.
Chapter 2: Overview of research system, empirical research situation and
syngas transformation theory in Vietnam and in the world.
Chapter 3: Research results and discussion.
Conclusion: Summary of outstanding results of the thesis.
References
Appendix
The results of the thesis have been published in 5 articles published in local
and international journals.
Chapter 1. THEORY BASIS

6


Introduction of theoretical basis including the problems of quantum
chemical theory and theory of chemical dynamics such as: Schrodinger
equation, basic function, introduction of quantum chemical approximation
methods, transitional state theory ...

Chapter 2. LITERATURE REVIEW
2.1. Overview of research on syngas metabolism in the world
High alcohol synthesis directly from syngas was discovered by two
German scientists Frans Fischer and Hans Tropsch in 1923. This process was
promoted by many different types of catalysts and many researches on
mechanism. The reaction was carried out to find a suitable catalyst with high
alcohol selectivity. Catalysts for high alcohol synthesis can be divided into

four main groups: i) Catalytic modification of methanol synthesis process; ii)
Catalytic modification of Fischer-Tropsch (FT) process; iii) Catalyst based on
Mo; and iv) catalytic system based on Rh.
2.2. Researches in our country
In Vietnam nowadays, the issue of converting syngas into liquid fuel or
alcohol mixture from coal, natural gas or biomass sources has started to attract
research attention not only by scientists. Studying big industrial corporations.
However, the research results of the research groups are few (or not) widely
published in specialized scientific journals.
2.3. The objective of the thesis
Most syngas-based ethanol formation studies have focused on singlemetallic or bimetallic systems without carriers due to the computational burden
associated with complex reaction networks. However, it is clear from empirical
research that the addition of bimetal catalysts and the role of carriers are
necessary to use normal metals in place of precious metals but can still
Selectable ethanol. To evaluate the possibility of combining the two metals, we
used DFT simulation of all reactions associated with the formation of ethanol
from syngas.
Chapter 3: RESULTS AND DISCUSSION
All structural and energetic calculations in this thesis are done by DFT
method in the Generralized gradient approximation (GGA), the PBE exchange
correlation function, using the DZP base function set, the hypothesis full
standard Kleinman-Bylander Troullier-Martins form with cutoff function
equivalent to plane wave 2040.75 eV. The Brillouin-zone is sampled at point
Γ. Geometric optimized structures using the Quasi Newton algorithm with a
force convergence criterion of 0.05 eV/Å. The calculation method is integrated
in QUANTUM software, which is a software package that combines SIESTA
with NEB and some other features. The bond order is calculated by Mayer

7

method. The charge of atom is studied based on the Voronoi method.
Transition state is determined by CI-NEB method.
3.1. The hydrogenation of CO by the Ni-Cu catalyst supported on AC
3.1.1. Adsorption of H2, CO on NiCu/AC
When we bring the NiCu cluster to AC, we determine the most durable
structure, from which research the adsorption of CO and H2 on that structure.
- Adsorbed H2 on NiCu/AC: When H2 adsorbed on NiCu/AC, H2 was
dissociated when adsorbed onto NiCu/AC.
- CO adsorption on NiCu/AC: The
adsorption of CO on NiCu/AC has no
dissociation. The CO adsorption
processes on NiCu/AC are not through
transition state, great adsorption energy, Figure 3.1.11. The structures of CO
adsorption on NiCu and NiCu/AC
so the adsorption process happens
smoothly.
- When CO and H2 adsorbed on NiCu/AC, CO will adsorb first then H 2 will
adsorb to the next chemical reaction.
3.1.2. Convert CO and H2 on NiCu/AC.
Table 3.1.8. Adsorption energy and activation energy of CO and H2
conversion on NiCu/AC catalyst (kJ/mol).
Ni
NiCu
Cu
Reaction
∆E
Ea
∆E
Ea ∆E

Ea
R1 CO(g)+*→CO*
-246,6
-261,9 - -180,6
R2 H2(g)+*→2H*(H2*)
-66,1
-160,0 25,3 -55,0
R3 CO*+H*→CHO*+*
51,8 93,5 77,4 82,9 89,3 98,9
R4 CHO*+H*→CH2O*+*
-51,0 9,6
-94,8 0,3
R5 CH2O*+H*→CH3O*+*
-42,3 31,5 -51,8 40,3 -85,4 56,7
R6 CH3O*+H*→CH3OH*+*
117,2 170,7
54,2 150,5
R7 CH3OH*→CH3OH(g)+*
110,9
63,1
R8 CO*+H*→COH*+*
98,0 115,1
R9 CHO*+H*→CHOH*+*
97,3 204,2 0,2 119,1 60,9 190,0
R10 CH2O*+H*→CH2OH*+*
19,0 129,2
-4,2 50,7
R11 CH2O*→CH2O(g)+*
229,5
266,5

R12 COH*+H*→CHOH*+*
-21,6 44,3
R13 CHOH*+H*→CH2OH*+*
-5,0 27,6
-58,7 35,5
R14 CH2OH*+H*→CH3OH*+*
20,6 150,9
15,8 173,2
R15 COH*+H*→C*+H2O*
220,8 239,6
R16 CHOH*+H*→CH*+H2O(g) +*
89,2 106,6
R17 CH2OH*+H*→CH2*+H2O*
-74,8 83,7
R18 H2O*→H2O(g) +*
105,7
55,9
-

8


R19
R20
R21
R22
R23
R24
R25
R26

R27
R28
R29
R30
R31
R32
R33
R34
R35
R36
R37
R38
R39
R40
R41
R42
R43
R44
R45
R46
R47
R48
R49
R50
R51
R52
R53
R54
R55
R56

R57
R58

9

CH*+ H*→CH2*+*
CH2*+ H*→CH3*+*
CH3*+ H*→CH4(g) +2*
CH*+ CO→CHCO*+*
CH2*+ CO*→CH2CO*+*
CH3*+ CO*→CH3CO*+*
CHCO*+H*→CH2CO*+*
CH2CO*+H*→CH3CO*+*
CHCO*+H*→CHCHO*+*
CH2CO*+H*→CH2CHO*+*
CH3CO*+H*→CH3CHO*+*
CHCHO*+H*→CH2CHO*+*
CH2CHO*+H*→CH3CHO*+*
CH3CHO*→CH3CHO(g) +*
CHCHO*+H*→CHCH2O*+*
CH2CHO*+H*→CH2CH2O*+*
CH3CHO*+H*→ CH3CH2O*+*
CHCH2O*+H*→CH2CH2O*+*
CH2CH2O*+H*→CH3CH2O*+*
CH3CH2O*+H*→CH3CH2OH*+*
CHCH2O*+H*→CHCH2OH*+*
CH2CH2O*+H*→CH2CH2OH*+*
CHCH2OH*+H*→CH2CH2OH*+*
CH2CH2OH*+H*→CH3CH2OH*+*
CHCO*+H*→CHCOH*+*

CH2CO*+H*→CH2COH*+*
CH3CO*+H*→CH3COH*+*
CHCOH*+H*→CH2COH*+*
CH2COH*+H*→CH3COH*+*
CHCOH*+H*→CHCHOH*+*
CH2COH*+H*→CH2CHOH*+*
CH3COH*+H*→CH3CHOH*+*
CHCHOH*+H*→CH2CHOH*+*
CH2CHOH*+H*→CH3CHOH*+*
CH3CHOH*+H*→CH3CH2OH*+*
CH3CH2OH*→ CH3CH2OH(g)+2*
CHCHOH*+H*→CHCH2OH*+*
CH2CHOH*+H*→CH2CH2OH*+*
CHCH2OH*+H*→CH2CH2OH*+*
CH2CH2OH*+H*→CH3CH2OH*+*

-140,5 4,8
-125,3 39,7
109,0 112,4
50,9
33,2
-36,9
-76,2
-27,0
-76,2
-2,5
-99,5
10,4
193,6
20,5

-15,0
-101,8
-136,4
-46,8
81,6
-34,3
-2,6
-100,4
49,8
72,7
-58,8

51,5
110,7
75,3
23,1
44,8
72,5
49,6
38,7
72,4
81,5
56,4
56,7
80,2
79,4
113,1
146,6
47,9
18,6

79,7
95,6
10,3

-143,4 113,8
-94,9
9,4
-9,6
-143,4
-16,4
37,3
109,0
-5,4
-85,4
-100,4
49,8

123,6
38,5
46,8
113,8
91,9
149,6
90,9
175,7
18,6
79,7

-95,5
94,7 234,8 112,4

-267,8 -29,6
77,1
-26,2
-49,7 124,6 -25,4
-68,6
-59,0
-19,7
-76,1
24,6
233,4
28,7
-0,1
-67,6 53,1 -46,8
-101,7
-96,0
95,4
-61,9
-46,0
-108,1
81,7
108,0
-34,4
59,4 104,6
-74,1
15,9 195,6
-67,2
7,7
-45,3
55,6
-154,4

31,3
87,3
-26,6
-67,6
-108,1
81,7

6,7
218,7
67,1
108,4
58,9
205,3
63,7
43,9
72,5
21,7
109,3
209,6
269,2
79,4
77,9
89,8
121,5
74,8
39,1
22,5
162,2
184,6
132,4

75,4
125,4
161,4
47,1
140,4
51,1
122,6
97,8
226,8
22,5
162,2


R59
R60
R61
R62
R63
R64

CHCHO*+H*→CHCHOH*+*
-32,4 58,5
17,7 50,9
CH2CHO*+H*→CH2CHOH*+*
74,6 156,8
38,4 150,5
CH3CHO*+H*→CH3CHOH*+*
-10,3 93,8
-109,4 84,2
CHCHOH*+H*→CH2CHOH*+*

71,4 101,0
55,6 140,4
CH2CHOH*+H*→CH3CHOH*+*
-16,4 91,9
-154,4 51,1
CH3CHOH*+H*→CH3CH2OH*+*
37,3 149,6
30,0 151,0
Note: The symbol* refers to the adsorbent on the catalytic system or an
empty surface position.
From the calculated results, we propose a convenient reaction pathways for
the formation of C2H5OH* from CO as follows:
*
*
*
*
*
CO* 2H CH2O* H CH2OH* H CH2* H CH3* H
CH4(g)
R3, R4
R20
R10
R17
R21
CO* R24
H2(g)
2H*
R2
CH3CO*
3H* R29, R35, R38, R54

CH3CH2OH(g)

CO(g)

R1

Figure 3.1.22. Reaction network form ethanol on NiCu/AC catalysts.
The process of calculating 127 reactions shows that the use of Ni-Cu
bimetallic supported on AC is completely favorable. Bimetallic position
reduces energy to reduce activation energy of CO insertion reaction,
hydrogenation reactions for intermediates CH3*.
CH2O(g)
CO*

CHO*

CH2O*

COH*

CHOH*

CH2OH*

C*

CH*
CHCO*

CHCOH*

CH3*

CH4(g)

CH3OH(g)

CO*

CH3COH*
CH3CHO*

CH3CHOH*

CH2CH2O*

CH2CH2OH*

CH3OH*

CH3

CH2CHO*

CH2CHOH*

CHCH2O*
CHCH2OH*

CH2CO*

CH2COH*

CHCHO*
CHCHOH*

CH2*

CH3O*

CH3CHO(g)
CH3CH2OH*

CH3CH2OH(g)

CH3CH2O*

Figure
3.1.25. The Fischer - Tropsch reaction diagrams of CO with H2 by Ni-Cu
catalyst system supported on activated carbon.
3.2. The hydrogenation of CO by the Ni2Cu2 catalyst on AC

10


3.2.1. Adsorption of H2, CO on Ni2Cu2/AC

Figure 3.2.2. Structures of Ni2Cu2/AC (bond lengths in Å).
The most stable Ni2Cu2 structure corresponds to the diamond shape (cis
form, with two Ni atoms close together.) We then studied the interaction of

Ni2Cu2 with AC and found the most stable Ni2Cu2/AC structure (Figure 3.2. 2).
- When adsorbed H2 on Ni2Cu2/AC, H2 adsorbed molecules dissociated
with Eads = -186.9 kJ/mol and did not pass through TS.
- When adsorbed CO on Ni2Cu2 or Ni2Cu2/AC, the adsorption processes
have very negative adsorption energy with Eads = -235.1 kJ/mol and do not go
through TS.
3.2.2. Convert CO and H2 on Ni2Cu2/AC
Table 3.2.6. Energy variation (ΔE, kJ/mol), activation energy (Ea, kJ/mol) of CO
conversion on Ni, Cu and Ni-Cu catalyst centers
Ni
NiCu
Cu
Reaction
∆E
Ea
∆E
Ea
∆E
Ea
R1 CO(g)+*→CO*
-228,2
-235,1
-183,2
R2 CO*→C* + O*
292,5 315,9
R3 CO*+H*→CHO*+*
11,8 83,6 -11,8 24,2 74,3 86,6
R4 CHO*+H*→CH2O*+*
-30,0 85,5 -48,8 31,9 1,5 63,3
R5 CH2O*+H*→CH3O*+*

-70,4
-39,2 70,9 -42,5
R6 CH3O*+H*→CH3OH*+*
-23,7 42,2 36,0 138,4 -5,2 45,4
R7 CH3OH*→CH3OH(g)+*
128,1 108,4
35,2 58,9
R8 CHO*→CH*+O*
134,2 147,6
R9 CH2O*→CH2*+O*
88,5 113,0
R10 CH3O*→CH3*+O*
6,0 177,0 -41,9 175,3 5,6 128,7
R11 CO*+H*→COH*+*
126,7 147,4
R12 CHO*+H*→CHOH*+*
85,0 137,2
R13 CH2O*→HCHO+*
184,6
192,7
R14 CH2O*+H*→CH2OH*+*
-86,8 12,3
R15 COH*+H*→CHOH*+*
-50,7 68,6
R16 CHOH*+H*→CH2OH*+*
-83,7 35,8
R17 CH2OH*+H*→CH3OH*+*
52,3 56,6
56,6 212,5
R18 CH2OH*+H*→CH3OH(g)+*

73,0 213,9 87,5 275,0 180,5 209,6
R19 COH*+H*→C*+H2O*
-110,1 78,9
R20 CHOH*+H*→CH*+H2O +*
-110,1 78,9
R21 CH2OH*+H*→CH2*+H2O*
9,6 79,6

11


R22
R23
R24
R25
R26
R27
R28
R29
R30
R31
R32
R33
R34
R35
R36
R37
R38
R39
R40

R41
R42
R43
R44
R45
R46
R47
R48
R49

CH*+ H*→CH2*+*
CH2*+ H*→CH3*+*
-75,9
CH3*+ H*→CH4(g) +2*
45,7
CH*+ CO*→CHCO*
CH2*+ CO*→CH2CO*
CH3*+ CO*→CH3CO*
33,7
CHCO*+H*→CH2CO*
-38,2
CH2CO*+H*→CH3CO*
CHCO*+H*→CHCHO*
CH2CO*+H*→CH2CHO*
CH3CO*+H*→CH3CHO*
13,5
CH2CHO*+H*→CH3CHO*
CH3CHO*→CH3CHO(g) +*
139,4
CH2CHO*+H*→CH2CH2O*

CH3CHO*+H*→ CH3CH2O*
CH3CH2O*+H*→CH3CH2OH*+*
118,9
CHCO*+H*→CHCOH*
CH2CO*+H*→CH2COH*
CH3CO*+H*→CH3COH*
165,4
CH3COH*+H*→CH3CHOH*
CH3CHOH*+H*→CH3CH2OH*
19,9
CH3CH2OH*→ CH3CH2OH(g)+*
71,3
CH3CHOH*+H*→CH3CH2OH(g)+2* 97,6
CH3CHO*+H*→CH3CHOH*
H2(g)+*→2H*(H2*)
-78,0
H2O*→H2O(g) +*
102,3
O*+H*→OH* +*
OH* +H*→H2O+*
-15,1

12

-66,4 0,4
9,3 -97,5
89,5 58,8 109,1
-48,0 21,7
28,4
158,3 30,0 123,4

43,7
-5,2 84,0
21,3 58,4
-113,8 36,5
53,0
115,5
-17,6
135,8 195,5
63,5
46,5
192,7
-44,9
63,6
141,4
108,4
-186,9
-153,6
37,5

-18,7 49,2
63,0 101,4

130,9 259,6
-3,0 142,8

-15,3 103,0
98,2 187,9
162,7
-

226,0
77,3
288,1 110,9 137,2
122,4
233,8
83,8 276,4
8,6 -79,5 87,4
31,4

44,4

238,3 111,6 183,7
-56,9
92,1 103,3
24,8
-29,7 91,2


0,0

-374,1
(R6)

-416,3

CH2*+H2O*

-333,1
-381,1
(R7)

CH3OH(g)

-342,7

(R5)

-400

CH3OH(g)

-263,1
-257,4
-255,2 (R21)
-287,6
-286,1
(R17) -290,4 (R10)

-333,6
(R14)

-345,9

-231,5
(R7)

CH3*+O*+H*

-297,1

-350

-232,9
(R9)

CH3OH*

-285,3

-300

-212,1
-265,2
(R4)

CH3OH*

-261,1
(R3)

CH2*+O*+H2(g)

-235,1

-161,3
(R13)

CH2O*+H2(g)

CO*+2H2(g)

-250

CO*+2H*+H2(g)

Energy, kJ mol-1

-200

CHO*+H*+H2(g)

-149,5
-159,9
(R11)
(R8)
-151,1
-162,0 (R12)

CH3O*+H*

-137,9
-150

CH2OH*+H*

-100

CHOH*+H2(g)

COH*+H*+H2(g)

-50

CH*+O*+H*+H2(g)

CO(g)+2H 2(g)

-404,8

-410,7

-440,0

-450

Figure 3.2.7. Reactions pathways of CO conversion on the catalyst centers of
Ni2Cu2/AC system form HCHO, CH3OH, CH2*.

(R34)

85,4

57,6
23,3
(R36)

15,8
-14,5
(R32)

-53,2

-54,0
CH3CHO*+H2(g)

64,2
(R37)

C2H5OH(g)

CH3CH2OH*

97,9

CH3CHOH*+H*

129,7
(R45)

91,7
(R43)

47,3

-71,6
CH3CH2O*+H*

CH2CH2O +H2(g)

*

CH3CHO*+2H2(g)

-99,7

125,2
(R40)

CH2CHOH*+H2(g)

-150

-67,5

CH2CHO*+H*+H2(g)

-100

-97,5
(R23)

126,3
(R35)

-1,5

14,1

-51,8

-50

88,2
(R33)

CH3CO*+H*+H2(g)

-8,0
(R24)

25,9
(R27)

CH4(g)+CO +2H2(g)

0,0

28,4

CH3CO*+H*+H2

CH2CO +3H2(g)

*

(R26)

103,3
(R29)
(R31)

50,6

*

50

CH3*+CO*+H*+2H2(g)

Energy, kJ mol-1

100

(R39)
134,1

CH2*+CO*+2H*+2H2(g)

150

CH3CHO(g)+H2(g)

CH2COH*+H*+H2(g)
65,8

200

CH3COH*+H2(g)

253,1
(R39)

250

Figure 3.2.9. Reactions pathways of CO conversion on the catalyst centers of
Ni2Cu2/AC system forms CH4, CH3CHO, CH3CH2OH.

13


In this section, we have calculated 85 intermediate reaction steps in the
proposed reaction mechanism of ethanol synthesis from CO and H2 mixture on a
Ni2Cu2 cluster catalyst supported on AC. The key to the formation of ethanol on
a bimetallic cluster is still the presence of the bimetallic interface, which
effectively reduces the activation energy of the CO insertion reaction, the
hydrogenation reactions for CH3*. Unlike NiCu/AC catalyst (main product is
methane and ethanol), Ni2Cu2/AC catalyst can also produce methanol.
3.3. The hydrogenation of CO by the Ni 2Cu2 catalyst supported on
magnesium oxide (MgO)
3.3.1. Adsorption of H2, CO on Ni2Cu2/MgO
The research results have shown the most stable adsorption structure of
Ni2Cu2 on MgO, thereby finding the most stable H 2, CO adsorption structure
on Ni2Cu2/MgO.

Figure 3.3.3. Structures
Figure 3.3.4. Structures
Figure 3.3.5. Structures
of Ni2Cu2/MgO (bond
of H2 adsorption on
of CO adsorption on
lengths in Å)

Ni2Cu2/MgO
Ni2Cu2/MgO
3.3.2. Convert CO and H2 on Ni2Cu2/MgO
Table 3.3.5. Energy variation (ΔE, kJ/mol), activation energy (Ea, kJ/mol) of CO
conversion on Ni, Cu and Ni-Cu catalyst centers
Ni
NiCu
Cu
Reaction
∆E Ea ∆E Ea ∆E
Ea
R1 CO(g)+*→CO*
-257,9
-263,0
-181,1
R2 CO*→C* + O*
266,4 329,1
R3 CO*+H*→CHO*+*
60,3 101,7 87,1 94,1 116,0 126,0
R4 CHO*+H*→CH2O*+*
32,5 72,5 -36,1 64,9
R5 CH2O*+H*→CH3O*+*
-144,1 43,7
R6 CH3O*+H*→CH3OH*+*
155,7 278,1
104,7 140,8
R7 CH3OH*→CH3OH(g)+*
43,7 114,8
87,1
R8 CHO*→CH*+O*

98,7 143,3
R9 CH2O*→CH2*+ O*
-33,5 116,2
R10 CH3O*→CH3*+O*
21,3 72,0
51,2 111,6
R11 CO*+H*→COH*+*
110,7 189,0
R12 CHO*+H*→CHOH*+*
26,7 48,3
R13 CH2O*+H*→CH2OH*+*
-77,9 3,2
54,3 135,7
R14 COH*+H*→CHOH*+*
10,1 143,2
R15 CHOH*+H*→CH2OH*+*
42,6 44,4
-59,7 13,6

14


R16
R17
R18
R19
R20
R21
R22
R23

R24
R25
R26
R27
R28
R29
R30
R31
R32
R33
R34
R35
R36
R37
R38
R39
R40
R41
R42
R43
R44
R45
R46
R47
R48
R49
R50
R51
R52
R53

R54
R55

15

CH2OH*+H*→CH3OH*+*
CH2OH*+H*→CH3OH(g)+*
COH*+H*→C*+H2O*
CHOH*+H*→CH*+H2O +*
CH2OH*+H*→CH2*+H2O*
C*+ H*→CH*+*
CH*+ H*→CH2*+*
CH2*+ H*→CH3*+*
CH3*+ H*→CH4(g) +2*
CH*+ CO*→CHCO*
CH2*+ CO*→CH2CO*
CH3*+ CO*→CH3CO*
CHCO*+H*→CH2CO*
CH2CO*+H*→CH3CO*
CHCO*+H*→CHCHO*
CH2CO*+H*→CH2CHO*
CH3CO*+H*→CH3CHO*
CHCHO*+H*→CH2CHO*
CH2CHO*+H*→CH3CHO*
CH3CHO*→CH3CHO(g) +*
CHCHO*+H*→CHCH2O*
CH2CHO*+H*→CH2CH2O*
CH3CHO*+H*→ CH3CH2O*
CHCH2O*+H*→CH2CH2O*
CH2CH2O*+H*→CH3CH2O*

CH3CH2O*+H*→CH3CH2OH*+*
CHCH2O*+H*→CHCH2OH*
CH2CH2O*+H*→CH2CH2OH*
CHCH2OH*+H*→CH2CH2OH*
CH2CH2OH*+H*→CH3CH2OH(g)+*
CH2CH2OH*+H*→CH3CH2OH*
CHCO*+H*→CHCOH*
CH2CO*+H*→CH2COH*
CH3CO*+H*→CH3COH*
CHCOH*+H*→CH2COH*
CH2COH*+H*→CH3COH*
CHCOH*+H*→CHCHOH*
CH2COH*+H*→CH2CHOH*
CH3COH*+H*→CH3CHOH*
CHCHOH*+H*→CH2CHOH*

0,484 220,1
75,2
18,7 93,5 84,2 92,9 -59,0
14,3 74,9
13,0
-75,5 91,9
-3,1 44,0
-167,8 17,1
8,5 57,3
-63,8 120,6 -110,7 18,6 -110,0
55,7 177,6 53,1 72,1 60,3
36,7 192,9 67,1 108,0 25,4
76,1 106,5 67,2 78,3 4,6
76,0 119,6 36,2 84,5 37,7

24,7 79,7 4,7 111,1 -48,0
-137,1 20,5 -10,5 33,2 90,9
-54,4 68,2 -4,3 90,6 -50,9
-72,1 42,5 10,5 68,4 -110,7
46,5 157,3
28,7
-25,8 46,1
-50,3
-83,6 177,6 -17,0 72,7
186,7 238,2
20,6 76,1 22,3 100,9 -34,9
21,7 43,6 -23,2 58,7 81,8
-47,0 36,2
-59,9 67,8 1,4 41,5 67,0
-21,2 77,8 -117,2 61,5 -56,3
35,3 78,4
173,9
6,4 122,5 21,0
19,5 77,9 -23,1 39,5 115,5
-162,7 41,6 -21,4 52,3 -39,2
61,5 119,4 79,0 173,6
82,8 119,6 41,3 104,1 -26,7
-11,0 41,4
32,6
-72,7 26,6 67,9 -61,4
181,8 199,4
163,9
26,6 67,9
-65,0 134,3 89,2
9,0 88,9

-24,1
-2,2 132,3 -41,4 24,6 9,9
-73,4 57,1 5,9 85,0 58,1
-61,9 79,5
29,5

91,6
102,4
19,1

102,2
171,1
96,7
99,2
206,6
87,0
175,8
62,5
59,1
144,7
49,1
269,2
58,8
157,6
100,8
40,8
283,3
286,9
133,7
61,5

169,4
179,5
34,5
204,7
306,5
26,5
71,0
65,8
77,8


R56
R57
R58
R59
R60
R61
R62
R63
R64
R65
R66
R67
R68

CH2CHOH*+H*→CH3CHOH*
CH3CHOH*+H*→CH3CH2OH*
CH3CH2OH*→ CH3CH2OH(g)+*
CH3CHOH*+H*→CH3CH2OH(g)+2*
CHCHOH*+H*→CHCH2OH*

CH2CHOH*+H*→CH2CH2OH*
CHCHO*+H*→CHCHOH*
CH2CHO*+H*→CH2CHOH*
CH3CHO*+H*→CH3CHOH*
H2(g)+*→2H*(H2*)
H2O*→H2O(g) +*
O*+H*→OH* +*
OH* +H*→H2O(g) +*

-14,0 87,5
-53,9 43,3
78,9 116,5
1,4 81,0
1,4 49,5
-70,8 26,6
-20,2 31,4
76,7 142,4
-7,0 97,2
-154,1
91,1
-

157,5
-8,2
-52,5
30,2
6,8
64,3

-59,8

187,7

66,9 310,7
60,4 138,4
23,1 72,7
172,5 75,0 88,8
144,4
52,9 41,4 52,3
59,3 84,7 128,2
238,0 13,7 89,9
-199,5
89,2
83,4
275,7

Figure 3.3.14. Reaction pathways converts CO on the Ni2Cu2/MgO catalyst
to CH3OH*, CH2*.

16


Figure 3.3.15. Reaction pathways converts CH2* on Ni2Cu2/MgO catalyst to
ethanol.
Based on the calculation results, we propose a favorable reaction path for
the formation of C2H5OH from CO as follows:

Figure 3.3.13. Proposed preferred reaction network to form ethanol from
syngas mixture on Ni2Cu2/MgO catalyst.
In this section, we have calculated the activation energy parameters and
reaction energy variation of 147. The calculation results show that the

Ni2Cu2/MgO catalyst has the ability to catalyze the formation of effective
ethanol. In addition to the desired product of ethanol, the catalyst also forms
methane and methanol (like the Ni 2Cu2/AC catalyst), the role of the MgO has
not shown much difference.
3.4. The hydrogenation of CO by the Co2Cu2 catalyst supported on
MgO
3.4.1. Adsorption of H2, CO on Co2Cu2/MgO

Figure 3.4.2. Structures
of Co2Cu2/MgO (bond

17

Figure 3.4.3. Structures
of H2 adsorption on

Figure 3.4.4. Structures of
CO adsorption on Co2Cu2


R1
R2
R3
R4
R5
R6
R7
R8
R9
R10

R11
R12
R13
R14
R15
R16
R17
R18
R19
R20
R21
R22
R23
R24
R25
R26
R27
R28

length in Å)
Co2Cu2/MgO
and Co2Cu2/MgO
3.4.2. Convert CO and H2 on Co2Cu2/MgO
Table 3.4.6. Energy variation (ΔE, kJ/mol), activation energy (Ea, kJ/mol) of CO
conversion on Co, Cu and Co-Cu catalyst centers
Co
CoCu
Cu
Reaction
∆E

Ea
∆E
Ea
∆E
Ea
CO(g)+*→CO*
-231,2
-214,3
-180,9
CO*→C* + O*
216,2 333,7
CO*+H*→CHO*+*
78,8
CHO*+H*→CH2O*+*
-0,1 49,8
CH2O*+H*→CH3O*+*
42,4 120,1
CH3O*+H*→CH3OH*+*
102,9 157,3 58,8 92,0 140,8
CH3OH*→CH3OH(g)+*
107,6
96,7 157,3
CHO*→CH*+O*
-6,2 296,8
CH2O*→CH2*+ O*
-30,0 178,3
CH3O*→CH3*+O*
-132,9 100,0
CO*+H*→COH*+*
210,1 266,2

CHO*+H*→CHOH*+*
114,8 128,3
CH2O*+H*→CH2OH*+*
155,0 167,0
CH2O*→HCHO(g) +*
221,7
CH3*+ H*→CH4(g)+2*
38,5 116,8
CH3*+ CO*→CH3CO*
83,5 124,5
CH3CO*+H*→CH3CHO*+*
12,1 100,1
CH3CHO*→CH3CHO(g) +*
235,1
CH3CHO*+H*→ CH3CH2O*+*
-1,1 85,2
CH3CH2O*+H*→CH3CH2OH*+* 133,7 274,3
30,0 88,9
CH3CH2OH*→ CH3CH2OH(g)+*
96,4
67,3 107,3
CH3CO*+H*→CH3COH*+*
90,1 105,3
CH3COH*+H*→CH3CHOH*+*
-31,6 123,6
CH3CHO*+H*→CH3CHOH*+*
51,7 124,8
CH3CHOH*+H*→CH3CH2OH*+*
100,4 169,4
H2(g)+*→2H*(H2*)

-167,7
-157,8
O*+H*→OH* +*
-126,2 58,3
OH*+H*→H2O(g) +*
113,9
-

18


CO*+2H*+H2(g)

-300

-400

-289,3
(R4)

-339,1

-224,3

-339,2

CH2OH*+H*

-172,2
(R13)

-160,9
(R9)
-197,0
(R10)

-184,2

-219,1
(R5)

-130,6
(R7)
CH3OH*

CHO*+H*+H2(g)

-234,1

-350

-210,8
(R12)

-207,8

(R14)

-205,0
(R6)

CH3O*+H*

-200

CHOH*+H2(g)

CO*+2H2(g)

Energy, kJ mol-1

(R11)

-117,5

CH2O*+H2(g)

-151,7

-150

-250

COH*+H*+H2(g)

-100

-238,2

-297,0

-345,3

CH2*+O*+H2(g)

(R8)

CH3*+O*+H*

-42,3
-50

CH3OH(g)

HCHO(g)+H2(g)

CO(g)+2H2(g)

CH*+O*+H*+H2(g)

0,0

-369,2

(R3)

-417,9

-429,9

-450

Figure 3.4.9. Reaction pathways of CO conversion on Co-Cu catalyst centers
of Co2Cu2/MgO system form HCHO, CH3OH, CH3*.

50

95,6

173,6

(R19)

147,3

142,0

CH3CH2OH*

CH3CH2OH

244,7

242,4
183,4
(R20)

349,7
(R21)
CH3CH2OH(g)

220,4
(R24)
180,8

*

297,2
(R23)

311,4
(R25)

CH3CH2OH*

116,8
(R15)

183,6
(R17)

(R22)
188,8
CH3CHO*+H2(g)

100

(R16)
124,5
CH4(g)+O*

150

CH3CO*+H*+H2(g)

200

CH3*+CO*+H*+H2(g)

Energy, kJ mol-1

250

CH3COH*+H2(g)

(R18)

316,7
(R25)

CH3CHOH*+H*

300

355,0
(R21)

CH3CH2O*+H*

CH3CHO(g)+H2(g)

330,7

CH3CHOH*+H*

350

315,0
306,1

220,9

(R21)

124,5

94,5

83,5

38,5

0,0
-50

Figure 3.4.10. Reaction pathways of CH3* on Co-Cu catalyst centers of
Co2Cu2/MgO form CH4, CH3CHO, CH3CH2OH.
Based on the calculation results, we propose a favorable reaction path for
the formation of C2H5OH from CO as follows:

19

Figure 3.4.12. Reaction network give preference to ethanol from syngas mixture
on Ni2Cu2/MgO catalyst.
In this section, we calculated the activation energy parameters and reaction
energy variations of 36 reaction steps. The calculation results show that the
Co2Cu2/MgO catalytic system has the ability to catalyze the formation of
effective ethanol. In addition to the desired product is ethanol, there are still
other products such as methane and methanol.
3.5. The hydrogenation of CO by the Co4, Cu4 catalyst supported on
Al2O3
3.5.1. Adsorption H2, CO on M4 và M4/Al2O3
In this study, the Al2O3 model (104) was selected as the supporter for the
metal catalyst. We have studied the cluster structure of Co 4 and Cu4, selected
the most durable structure and adsorbed on Al 2O3. Then proceed to adsorb H2
on M4/Al2O3 and CO on M4 and M4/Al2O3 to compare and select the most
stable adsorption configuration to continue conversion.

Figure 3.5.5. Structures of CO
Figure 3.5.6. Structures of CO
adsorption on Co4 and Co4/Al2O3
adsorption on Cu4 and Cu4/Al2O3
3.5.2. Convert CO and H2 on M4/Al2O3 into CH3OH
3.5.2.1. Convert CO and H2 on Co4/Al2O3 into CH3OH
Table 3.5.6. Energy variation (ΔE, kJ/mol), activation energy (Ea, kJ/mol) of
CO conversion on Co4/Al2O3 catalyst centers
Reaction
∆E
Ea
R1

CO +* → CO*
-237,3
R2
H2 +* → 2H*
-280,7
R3
CO* + H* → COH* +*
149,1
R4
COH* + H* → CHOH* +*
-5,2
83,0
R5
CHOH* + H2(g) → CH2OH* + H*
-97,8
2,1
R6
CH2OH* + H2(g) → CH3OH(g) + H*
-22,4
173,5
R7
CHOH* + H* → CH2OH* +*
18,6
114,8
R8
CH2OH* + H* → CH3OH(g) +*
47,8
221,2
R9
CO* + H* → CHO* +*

212,2
-

20


R10

CHO* + H* → CH2O* +*

-6,9

73,4

Figure 3.5.7b. Reaction pathways of can occur through total hydrogenation of
CO on the Co4/Al2O3 catalyst
3.5.2.2. Convert CO and H2 on Cu4/Al2O3 into CH3OH
Table 3.5.7. Energy variation (ΔE, kJ/mol), activation energy (Ea, kJ/mol) of
CO conversion on Cu4/Al2O3 catalyst centers
Reaction
∆E
Ea
R1
CO +* → CO*
-238,2
R2
H2 +* → 2H*
-145,4
R3
CO* + H* → COH* +*

23,6
188,6
R4
COH* + H* → CHOH* +*
-50,7
100,5
R5
CO* + H* → CHO* +*
54,5
87,9
R6
CHO* + H* → CH2O* +*
31,2
54,2
R7
CH2O* → HCHO(g) +*
138,9
168,5
R8
CH2O* + H* → CH2OH* +*
-4,0
115,6
R9
CH2O* + H* → CH3O* +*
-69,4
71,2
R10 CH3O* +*H → CH3OH* +*
69,1
140,6
R11 CH3OH* → CH3OH(g) +*

117,2
R12 CHO* + H* → CHOH* +*
154,4
R13 CHOH* + H* → CH2OH* +*
-87,5
6,8
R14 CH2OH* + H* → CH3OH(g) + 2*
112,5
112,8

21


Figure 3.5.8. Reaction pathways of can occur through total hydrogenation of
CO on the Cu4/Al2O3 catalyst.
In this section, we calculated the activation energy and reaction energy
variations of 10 reactions in a proposed methanol synthesis mechanism from
the mixture of CO and H2 on Co4/Al2O3 and 14 reactions on Cu4/Al2O3.
Calculation results show that both catalyst systems have the ability to convert
CO into methanol, but Co4/Al2O3 catalysts have high Ea reactions, while most
Cu4/Al2O3 catalysts have Ea. not high. The study also showed the role of Al 2O3
supporter in catalytic stability.
3.6. The hydrogenation of CO by the Co2Cu2 catalyst supported on
aluminum oxide (Al2O3)
Table 3.6.5. Energy variation (ΔE, kJ/mol), activation energy (Ea, kJ/mol) of CO
conversion on Co, Cu and Co-Cu catalyst centers
Co
CoCu
Cu
Reaction

∆E
Ea
∆E
Ea
∆E
Ea
R1 CO(g)+*→CO*
-183,6 - -228,1
- -156,8 R2 CO*→C* + O*
274,2 309,5
R3 CO*+H*→CHO*+*
-45,4 28,6
R4 CHO*+H*→CH2O*+*
29,7 73,5
R5 CH2O*+H*→CH3O*+*
-117,6 45,5
R6 CH3O*+H*→CH3OH*+*
34,2 108,4
39,9 84,0
R7 CH3OH*→CH3OH(g)+*
103,3 89,2 118,5
R8 CHO*→CH*+O*
291,0 302,9
R9 CH2O*→HCHO(g)+*
205,6
-

22

R10
R11
R12
R13
R14
R15
R16
R17
R18
R19
R20
R21
R22
R23
R24
R25
R26
R27
R28
R29
R30
R31
R32
R33
R34
R35
R36
R37
R38
R39

R40
R41
R42
R43
R44
R45
R46

CH2O*→CH2*+ O*
-97,7 30,5
CH3O*→CH3*+O*
-22,0 74,0 52,1 115,4 4,7 74,9
CO*+H*→COH*+*
24,8 119,8
CHO*+H*→CHOH*+*
38,3 148,3
CH2O*+H*→CH2OH*+*
-76,3 44,5
CH2OH*+H*→CH3OH*+*
24,5 167,0
CH2OH*+H*→CH2*+H2O
-7,4 65,5
CH*+ H*→CH2*+*
-101,4 33,4
CH2*+ H*→CH3*+*
-141,3 5,0
CH3*+ H*→CH4(g) +2*
-4,9 62,7
CH2*+ CO*→CH2CO*
15,5 44,1

CH3*+ CO*→CH3CO*
29,5 89,6
CH2CO*+H*→CH3CO*
-194,1 -215,8 41,1
CH2CO*+H*→CH2CHO*
-194,4 21,7
-188,6 53,1
CH3CO*+H*→CH3CHO*
11,0 139,8
39,5 89,1
CH2CHO*+H*→CH3CHO*
30,2 145,3
56,8 311,3
CH3CHO*→CH3CHO(g) +*
134,6 130,8 138,7
CH2CHO*+H*→CH2CH2O*
-3,1 107,6
11,7 95,4
CH3CHO*+H*→ CH3CH2O*
-84,0 12,2
-168,0 7,8
CH2CH2O*+H*→CH3CH2O*
-101,3 13,6
-94,3 111,1
CH3CH2O*+H*→CH3CH2OH*+* 71,6 131,0
62,2 134,4
CH2CH2O*+H*→CH2CH2OH*
-103,2 54,3
-66,0 102,7
CH2CH2OH*+H*→CH3CH2OH*

-62,9 35,1
CH2CO*+H*→CH2COH*
-78,4 131,1
-117,0 89,1
CH3CO*+H*→CH3COH*
147,3 71,1 154,2
CH2COH*+H*→CH3COH*
-19,0 180,7
CH2COH*+H*→CH2CHOH*
47,4 77,5
CH3COH*+H*→CH3CHOH*
-155,1 77,6
CH2CHOH*+H*→CH3CHOH*
-154,3 -84,1 125,4
CH3CHOH*+H*→CH3CH2OH*
43,7 174,1 -4,3 150,0 -100,3 86,4
CH3CH2OH*→ CH3CH2OH(g)+2* 99,2 102,5
61,7 84,4
CH2CHOH*+H*→CH2CH2OH*
41,7 94,8
-187,8 CH2CHO*+H*→CH2CHOH*
66,0 152,7
69,2 151,9
CH3CHO*+H*→CH3CHOH*
56,7 73,3
-151,0 21,4
H2(g)+*→2H*(H2*)
-53,5
- -193,8
-38,1

O*+H*→OH* +*
-9,1 65,5
OH* +H*→H2O(g) +*
-138,1 90,0
Based on the calculation results, we have built the reaction pathways and
proposed a convenient reaction path for the formation of CH 4, CH3OH,
C2H5OH* from CO as follows:

23


Figure 3.6.11. Reaction networks conversion on the Co2Cu2/Al2O3 catalyst.
In this section we calculated the activation energy parameters and reaction
energy variations of 73 intermediate reaction steps in a proposed ethanol
synthesis mechanism from a mixture of CO and H 2. Calculation results show
that the Co2Cu2/Al2O3 catalytic system has the ability to catalyze the formation
of ethanol efficiently. In addition, just like when using Ni 2Cu2/AC,
Ni2Cu2/MgO or Co2Cu2/MgO catalysts, in addition to the main product, there is
still the formation of methane and methanol.
3.7. Comparison of CO and H2 conversion on catalyst systems

24


Figure 3.7.1. The hydrogenation reaction pathways on the catalyst systems form CH2*, CH3* and CH3OH.