Computational Chemistry - thesis - full

1. Introduction

Water-Gas Shift reaction

Water-Gas Shift reaction

Simulation

Fossil fuels 87% of the world’s commercial energy

Mechanism of WGS

Investigating pathway of WGS reaction on Cu /ZnO

Doping & optimizing structure Cu /ZnO

Modeling & optimizing structure ZnO

Data of ZnO

Mechanism of WGS reaction

Copper

- Appropriate water-gas shift catalyst

- Cu/TiO > Cu/CeO > Cu/ZnO > Cu/MgO > Cu [1]

n

2

Carboxyl

Redox

COAL

GaussView :

+ Doping

+ View result

VASP :

- Optimization

+ Energy

+ Force

Cu/ZnO

Material studio:

+ Built

+ Cleave

+ Slap

Fishtik and Dutta (2002) [2]

Mao et al. (2008) [3]

Tang et al. (2009) [4]

Slide 22

Callaghan, C.A (2006)

4

Slide 17

Slide 18

[1] Peng, S.-F. and J.-J. Ho (2011)

NATURAL GAS

OIL

http://gasinvestingnews.com

Introduction

Alternative fuels

Introduction

Introduction

Steam reforming

Exhaust

- Cleaner

- More efficient

- Least influenced

Fuel cell

Introduction

Effects on environmental pollution and human healthy

Introduction

pH of 6.0

Kills insects, crabs

pH < 5.0

Kills fish, trees

Effects on land

Effects on air

Acid rain

6

en.wikipedia.org/pollution of environment

4

Pure hydrogen does not occur naturally

Manufacture

majority

en.wikipedia.org/solar energy

Combustion

CH = 1.5%

CO = 0.5%

CO = 24%

H = 74%

Air

• Device generates electricity by a chemical reaction.
• Every fuel cell has two electrodes :

+ One positive - Anode

+ One negative - Cathode.

Air

Fuel

CxHy

2

Hight concentration of CO

zero-emission

fuel

http://www.huffingtonpost.com/renewable energy

Not greenhouse gases

www.picstopin.com/biodiesel recycle

2

20 richest countries consume:

50% of coal

80% of natural gas

77% of oil

7

Non-toxic

Abundant

Water-gas shift reaction

8

9

Electrolysis

4

Introduction

4

Steam-methane reforming

Steam reforming 350 C - 500 C

CH = 0.2%

CO = 14.8%

CO = 14%

H = 71%

Water- gas shift reaction

CH = 0.2%

CO = 14.8%

CO = 14%

H = 71%

source: US. energy information administration 2012

Fuel

CxHy

2

o

Slide 14

2

www.green-planet-solar-energy.com

http://www.global-hydrogen-bus-platform.com/Technology/HydrogenProduction/reforming

2

11

5

www.fuelcells.org

Approach of calculation

http://americanhistory.si.edu/fuelcells/index.htm

Slide 13

10

source: US. energy information administration 2012

Steam H O

Slide 15

The reactions take place at the electrodes

Slide 12

Timeline of calculative process

2

Process of producing pure hydrogen

Vienna Ab-initio Simulation Package (VASP)

Materials Studio 6.0

+ Structure optimization

+ Test frequency of the optimizated structure

Gaussview

Slide 20

Conclusion

Modeling & optimizing structure ZnO

Review the result of VASP

+ Initial structure

+ Optimizated structure

Conversion of CO and H O

2

Investigating pathway of WGS reaction on Cu /ZnO (100)

Material Studio 6.0

+ simulated Structure of materials

+ Determination of material properties

H O* OH* + H*

2

6

CO* + OH* COOH*

cis

COOH* COOH*

cis

trans

Structure of ZnO

2

Before oftimization

After oftimization

COOH* CO * + H*

trans

2

Slide 21

Slide 19

1. CO and H O co-adsorption

2. Conversion of CO and H O

3. Desorption

CO + H

2 (g)

2

CO* CO

2

2 (g)

Optimized structure of ZnO

28

Slide 26

Slide 24

29

Thanks for your joining !

Conclusion

Doping & optimizing structure

Cu /ZnO(100)

CO and H O co-adsorption

n

kinetically favorable compared with that of clean ZnO(10ī0) surface.

2

Reference

co-ads

E = -1.67 (eV)

Prefer to adsorb at the Cu-site

Growth of Cu cluster

n

+ Shin-Ichiro Fujita, M.U.a.N.T., Mechanism of the Reverse Water Gas Shift Reaction over Cu/ZnO Catalyst. sciencedirect, 1991.

+ Cai, Y., J.P. Wagner, and J. Ladebeck, Low Temperature Water Gas Shift Reaction over Cu/Zn/Al Catalysts

+ Hung, J.-Y. and J.-C. Jiang, Density Functional Theory Study of Water Gas Shift Reaction on ZnO(1010) and Pd/ZnO(1010) Surfaces 2009. p. 1-90

+ Callaghan C, I.F., Ravindra Datta, An improved microkinetic model for the water gas shift reaction on copper. Surface Science, 2002

+ Tang Q L, Z.-X.C.a.X.H., A theoretical study of the water gas shift reaction mechanism on Cu (1 1 1) model system. Surface Science, 2009: p. 2138-2144

http://www.eajv.ca/english/H2

structure 6Cu/ZnO (100) surface

27

31

Hung, J.-Y. and J.-C. Jiang [2009]

Zhao, Y., et al [2011]

Slide 16

30

Slide 25

Slide 23

Kinetics and Mechanism of Water Gas Shift Reaction on 6Cu/ZnO catalyst

Tin Pham-1, Nguyen D. Vo -1, Lam K. Huynh -2

1 University of Technology, Vietnam National University - HCMC

2 Institute for Computational Science and Technology and International University, Vietnam National University, Ho Chi Minh City, Vietnam

Presenter : Tin Pham

2

November 30 2013

Computational chemistry

Outline

1- Introduction

2- Computational details

3- Results and discussion

4- Conclusion

3