Supplementary information for Theoretical study of O-assisted selective coupling of methanol

on Au(111)

Bingjun Xu1, Jan Haubrich

1, Thomas A. Baker

1, Efthimios Kaxiras

1,2,3, Cynthia M. Friend

1,2

1. Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138.

2. School of Engineering and Applied Sciences, Harvard University Cambridge MA 02138.

3. Department of Physics, Harvard University, Cambridge, MA 02139.

Table S1 Bond lengths in the transition state structure of different reaction steps shown

in Figures 1 and 2

Transition state structure Fig. Reaction pathway

Bond Bond length

(Å) Bond

Bond length

(Å) 1 CH3OH(a) + O(a) → CH3O(a) + OH(a) (CH3)O-H 1.28 O-HOCH3 1.17

1 CH3OH(a) → CH3O(a) + H(a) (CH3)O-H 2.07 Au-HOCH3 1.60

2 CH3O(a) → H2C=O(a) + H(a) O(H2)C-H 1.59 Au-HCH2O(a) 1.68

2 CH3O(a) + O(a) → H2C=O(a) + H(a) O(H2)C-H 1.24 HO-HCH2O(a) 1.38

2 CH3O(a) + OH(a) → H2C=O(a) + H2O(a) O(H2)C-H 1.33 HOH-CH2O(a) 1.28

2 CH3O(a) + CH3O(a) → H2C=O(a) +

CH3OH(a) O(H2)C-H 1.23 H3CO-HCH2O(a) 1.41

Table S2 The effect of the slab thickness and number of layers relaxed in the slab on the

adsorption energy of methanol # of layers in the

slab # of layers allowed to relax

Total energy (eV) Adsorption energy of methanol (eV)

Methanol/Au 5 1 -168.42 -0.08

Methanol/Au 5 2 -168.43 -0.09

Methanol/Au 4 1 -140.22 -0.09

Methanol/Au 4 2 -140.30 -0.09

Methanol/Au 3 1 -110.64 -0.10

Methanol/Au 3 2 -110.64 -0.10

Au 5 1 -138.01 -

Au 5 2 -138.01 -

Au 4 1 -109.81 -

Au 4 2 -109.89 -

Au 3 1 -80.23 -

Au 3 2 -80.23 -