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Electronic Supplementary Information for:

Oxidant free conversion of alcohols to nitriles over Ni-based catalysts

Yunzhu Wang,a Shinya Furukawa,bc Zhang Zhang,a Laura Torrente-Murciano,d Saif A. Khana and Ning Yan*a

a Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585, Singapore

b Institute for Catalysis, Hokkaido University, N-21, W-10, Sapporo 001-0021, Japan

c Elementary Strategy Initiative for Catalysis and Battery, Kyoto University, Kyoto Daigaku Katsura, Nishikyo-ku, Kyoto, Japan, 615-8510

d Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK

*Corresponding author.

E-mail address: ning.yan@nus.edu.sg (N. Yan).

Electronic Supplementary Material (ESI) for Catalysis Science & Technology.This journal is © The Royal Society of Chemistry 2018

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1. Thermodynamic data for the system

ΔrG of the reaction of converting hexanol to hexanenitrile can be calculated based on enthalpy

change (ΔrH, kJ/mol), entropy change (ΔrS, J/(mol K)) and temperature (T, K) of the reaction:

ΔrG = ΔrH – T * ΔrS (1)

Based on the reaction equation:

Hexanol + NH3 → Hexanenitrile + 2H2 + H2O (2)

ΔrH and ΔrS for eqn (2) can be expressed by the enthalpy of formation (ΔfH, kJ/mol) and entropy (S,

J/(mol K)) of the products and reactants:

ΔrH = ΔfH(Hexanenitrile) + 2*ΔfH(H2) + ΔfH(H2O) - ΔfH(Hexanol) - ΔfH(NH3) (3)

ΔrS = S(Hexanenitrile) + 2*S(H2) + S(H2O) - S(Hexanol) - S(NH3) (4)

Assuming the reactants and products are in gas phase during reaction, ΔfH and S of organic

compounds can be expressed as below based on “The Yaws’ Handbook of Thermodynamic

Properties for Hydrocarbons and Chemicals”1:

ΔfH(gas) = A + B*T + C*T^2 + D*T^3 + E*T^4 (5)

S(gas) = A + B*T + C*T^2 + D*T^3 + E*T^4 (6)

The coefficients are provided as:

A B C D E

ΔfH(gas)

Hexanol -280.24 -1.4316E-01 6.6191E-05 1.1787E-08 -9.4124E-12

Hexanenitrile 16.169 -9.5537E-02 2.7240E-05 2.7921E-08 -1.2146E-11

S(gas)

Hexanol 241.27 8.0226E-01 -5.4498E-04 3.2645E-07 -8.4288E-11

Hexanenitrile 217.85 7.7188E-01 -5.8082E-04 3.5641E-07 -9.1361E-11

According to “NIST-JANAF Themochemical Tables”,2 ΔfH and S of NH3, H2O, and H2 can be expressed

as

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ΔfH(gas) = A*(t) + B*(t)^2/2 + C*(t)^3/3 + D*(t)^4/4 – E/(t) +F (7)

S(gas) = A*ln(t) + B*(t) + C*(t)^2/2 + D*(t)^3/3 – E/(2*(t)^2) + G (8)

where, t = T/1000.

The coefficients of inorganic compounds are provided as below:

A B C D E F G

NH3 19.996 49.771 -15.376 1.9212 0.1892 -53.307 203.86

H2O 30.092 6.8325 6.7934 -2.5345 0.0822 -250.88 223.40

H2a 33.066 -11.363 11.433 -2.7729 -0.1586 - 172.71

aΔfH(H2) = 0, and the coefficients are only used for calculation of S(H2).

Combining eqns (1) to (8) and substituting the coefficients, both ΔrH and ΔrS are positive between

100 to 400 °C. Therefore, this reaction is high temperature, low pressure favoured, whose ΔrG is

negative from ca. 200 °C and above. Considering our experiments are conducted under low alcohol

partial pressure and that NH3 is supplied in large excess, the reaction is thermodynamically

favourable even at 190 °C.

2. DFT calculations

Periodic DFT calculations were performed using the CASTEP code3 with Vanderbilt-type ultrasoft

pseudopotentials4 and the revised version of the Perdew–Burke–Ernzerhof exchange–correlation

functional5 based on the generalized gradient approximation. The plane-wave basis set was

truncated at a kinetic energy of 360 eV. A Fermi smearing of 0.1 eV was utilized.

Geometry optimizations were performed on supercell structures using periodic boundary

conditions. The surfaces were modeled using metallic slabs with a thickness of four atomic layers

with 17 Å of vacuum spacing. A (3 × 3) unit cell was considered for adsorption on Ni(111) surface.

The reciprocal space was sampled using a 4 × 4 × 1 k-point mesh for the slab model, as generated by

the Monkhorst−Pack scheme.6 The convergence criteria for structure optimization and energy

calculation were set to (a) an SCF tolerance of 2.0 × 10−6 eV per atom, (b) an energy tolerance of

1.0 × 10−5 eV per atom, (c) a maximum force tolerance of 0.05 eV Å−1, and (d) a maximum

displacement tolerance of 1.0 × 10−3 Å.

The adsorption energy was defined as follows:

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Ead = EA-S–(ES + EA)

where EA-S is the energy of the slab together with the adsorbate, EA is the total energy of the free

adsorbate, and ES is the total energy of the bare slab. Spin-polarized condition was considered for

calculation of alkoxide molecule.

3. Catalysts characterization and control experiments

Table S1. BET surface area and Ni dispersion of catalysts.

Catalyst Surface Areaa (m2/g) Ni Dispersionb (%)

Ni/SiO2-DP 413.2 9.9 Ni/Al2O3-DP 185.3 8.3 Ni/SiO2-WI 171.8 3.5 Ni/Al2O3-WI 113.6 4.7 Ni/CaSiO3 163.8 3.1

a: BET surface area of catalysts estimated by N2-adsorption desorption analysis. b: Dispersion estimated by H2 chemisorption at room temperature by assuming one Ni atom adsorbs one H atom.

Fig. S1. TEM images of (a) Ni/Al2O3-DP, (b) Ni/Al2O3-WI, (c) Ni/SiO2-DP and (d) Ni/CaSiO3.

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Fig. S2. XRD patterns of Al2O3, Ni/Al2O3-DP and Ni/Al2O3-WI.

Fig. S3. Catalytic activity towards catalyst amount. Reaction conditions: Ni/Al2O3-DP catalyst, 130 ⁰C, 1 µL/min hexanol, 10 mL/min N2, 4 mL/min NH3.

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Fig. S4: Catalytic activity towards temperature. Reaction conditions: 50 mg Ni/Al2O3-DP catalyst, 1

µL/min hexanol, 10 mL/min N2, 4 mL/min NH3.

Fig. S5. Mass spectra of butylamine obtained by GC-MS analysis. Reaction conditions: 50 mg Ni/Al2O3-DP catalyst, 150 °C, 1 µL/min 1,1-dideuteriobutan-1-ol, 20 mL/min H2, 8 mL/min NH3.

(Text File) Scan 85 (3.201 min): 20180409-C3CD2-OH-150C-3H.D\ data.ms (-83)

25 30 35 40 45 50 55 60 65 70 75

0

12

24

26

27

28

30

31

37

38

39

40

41

42

4344

4549

50 51 52 53 54

55

56

5758 68 70

72

73

74

75

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Fig. S6. (a) Mass spectrum and (b) ESI mass spectra of 3,5-dibutyl-2-pentyl-pyridine (compound X).

Fig. S7. IR spectra of pyridine adsorbed on Ni/Al2O3-DP.

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Fig. S8. Plots of ln(Reaction rate) v.s. (a) ln(hexanol flow rate), hexanol flow rate was in unit of µL/min and flow rate of ammonia and nitrogen were 20 mL/min and 20 mL/min; and (b) ln(ammonia concentration), flow rate of 1-hexanol was 5 µL/min and total gas flow rate was 40 mL/min by supplementing nitrogen. Reaction rate was calculated as mmole of substrate converted per gram of catalyst per hour. 190 °C, 50 mg Ni/Al2O3-DP catalyst. GHSV = 6.4 × 104 h-1.

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Fig. S9. Optimized structures of O- and N- containing molecules adsorbed on Ni(111) surface. For

clarity, only the topmost layer of Ni(111) is shown.

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Table S2. Kinetic isotopic effects for converting 1-butanol to butanenitrile.

Alcohol

TOF (h-1)

KIE

1 1-CH3(CH2)3–OD 2.17 2 k1-CH3(CH2)3–OH / k1-CH3(CH2)3–OD 0.87

Reaction conditions: 160 °C, 1 µL/min substrate, 200 mg Ni/Al2O3-DP, 76 mL/min N2, 4 mL/min NH3.

GHSV = 3.21 x 104 h-1.

Fig. S10. DRIFTS of adsorbed species as a function of time under N2 flow at 130 °C on Ni/Al2O3-DP surface. At t = 0 min, (a) butanal and (b) 1-butylamine was injected.

Fig. S11. DRIFTS of adsorbed NH3 on Ni/Al2O3-DP surface and Al2O3 surface under N2 flow at 130 °C.

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Fig. S12. DRIFTS of adsorbed species as a function of time under N2 flow at 130 °C on NH3 saturated (a) Al2O3 surface, at t = 0 min, 1-butanol was injected and (b) Ni/Al2O3-DP surface, at t = 0min, 1-butanol-d was injected.

Table S3. Conversion of various primary alcohols to nitriles

Entry Substrate Product Temperature (⁰C) Yield

/Selectivity (%)

1a

230 44 /65

2

210 12 /20

3

190 8.0 /29

4

190 2.4 /8.7

5a

230 9.9 /15

Reaction conditions: 0.5 µL/min substrate, 200 mg Ni/Al2O3-DP, 20 mL/min N2, 8 mL/min NH3. a: 1 µL/min substrate.

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Fig. S13. ATR-IR spectroscopy of fresh Ni/Al2O3-DP catalyst, used Ni/Al2O3-DP catalyst after reaction between 1-butanol and NH3, and Ni/Al2O3-DP catalyst after DRIFTS analysis with butyronitrile.

References

1. C. L. Yaws, The Yaws Handbook of Thermodynamic Properties for Hydrocarbons and Chemicals, Gulf Publishing Company, Houston, Texas, United States, 1st edn., 2007.

2. M. W. Chase, Jr., NIST-JANAF Themochemical Tables, American Chemical Society, Maryland, United States, 1998.

3. M. D. Segall, P. J. D. Lindan, M. J. Probert, C. J. Pickard, P. J. Hasnip, S. J. Clark and M. C. Payne, J. Phys. Condens. Mat., 2002, 14, 2717-2744.

4. D. Vanderbilt, Phys. Rev. B, 1990, 41, 7892-7895. 5. B. Hammer, L. B. Hansen and J. K. Nørskov, Phys. Rev. B, 1999, 59, 7413-7421. 6. H. J. Monkhorst and J. D. Pack, Phys. Rev. B, 1976, 13, 5188-5192.