Supporting Information

Direct analysis at temporal and molecular level of deactivating coke species formed on zeolite catalysts with diverse pore topologies

Item Type Article

Authors Hita, Idoia;Mohamed, Hend Omar;Attada, Yerrayya;Zambrano, Naydu;Zhang, Wen;Ramírez, Adrian;Castaño, Pedro

Citation Hita, I., Mohamed, H. O., Attada, Y., Zambrano, N., Zhang, W., Ramírez, A., & Castaño, P. (2023). Direct analysis at temporal and molecular level of deactivating coke species formed on zeolite catalysts with diverse pore topologies. Catalysis Science &

Technology. https://doi.org/10.1039/d2cy01850k Eprint version Publisher's Version/PDF

DOI 10.1039/d2cy01850k

Publisher Royal Society of Chemistry (RSC) Journal Catalysis Science and Technology

Rights Archived with thanks to Catalysis Science and Technology under a Creative Commons license, details at: http://

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Link to Item http://hdl.handle.net/10754/688145

Supporting Information

Direct analysis at temporal and molecular-level of deactivating coke species formed on zeolite catalysts with diverse pore topologies

Idoia Hita,^a Hend Omar Mohamed,^a Yerrayya Attada,^a Naydu Zambrano,^a Wen Zhang,^b Adrian Ramírez,^c Pedro Castaño,^a*

a Multiscale Reaction Engineering, KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.

b King Abdullah University of Science and Technology, Imaging and Characterization Core Labs, Thuwal 23955, Saudi Arabia

c King Abdullah University of Science and Technology, KAUST Catalysis Center (KCC), Thuwal 23955, Saudi Arabia

* Corresponding author: pedro.castano@kaust.edu.sa

Electronic Supplementary Material (ESI) for Catalysis Science & Technology.

This journal is © The Royal Society of Chemistry 2023

Supplementary Figures

0.0E+00 2.0E+10 4.0E+10 6.0E+10 8.0E+100 2

4 6 8 10

Concentration (wt%)

Area (a.u.)

y=1.775E^-22x²+9.136E^-11x+7.594E^-2 R²=0.9999

Figure S1 Calibration curve used to calculate the soluble coke concentration.

0.0 0.2 0.4 0.6 0.8 1.0

0 100 200 300 400 500 600

Adsorbed volume (cm3 g-1 )

Relative pressure (P/P₀)

NiY NiZ₄₀ NiZ₁₅ Ni

Figure S2. N2 adsorption-desorption isotherm for all fresh zeolite-based catalysts.

The bimodal distributions of the NH3-TPD profiles (Figure S3) allow their Gaussian deconvolutions to estimate the contributions of the different types of acidity in the catalysts, namely a mild acidity (a1) and a stronger acidity (a2) presenting a higher temperature NH3

desorption peak. The temperatures of the maximum values of each peak are designated as T1 and T2, respectively. Overall, the NiZ15 catalyst (the most acidic) has the highest proportion of weaker acidic sites (70.6 %). While the weaker acidity peaks for the NiY, NiZ15,and NiZ40 catalysts have maxima at T1 = 281-292 ^oC, the same peak for the Niß catalyst presents its maximum at T1 = 257

°C, indicating a weaker nature for the a1 sites by comparison. This is analogous to what is observed for the a2 acidic sites, where the maximum for the Niß peak is located at 341 °C, 23-42 ^oC less than for the higher acidity peaks of the other catalysts. This denotes that the Niß catalyst has the overall weakest acidic sites of all the studied catalysts.

100 200 300 400 500

0 50 100 150 200 250

100 200 300 400 500

0 50 100 150 200 250

100 200 300 400 500

0 50 100 150 200 250

100 200 300 400 500

0 50 100 150 200 250

TCD signal (% g

-1 ca)t

Temperature (^oC)

TCD signal (% g

-1 ca)t

Temperature (^oC) NiY

NiZ₁₅

NiZ₄₀

Ni

a b

d c

TCD signal (% g

-1 ca)t

Temperature (^oC)

TCD signal (% g

-1 ca)t

Temperature (^oC)

Figure S3 Deconvolution of the NH3-TPD curves for all zeolite-based catalysts.

The acid properties were further investigated by pyridine adsorption infrared spectra (Figure S4). All catalysts exhibit three different peaks at the ∼1545, ∼1455, and 1491 cm⁻¹ bands that are attributed to the Brønsted acid sites (BASs), Lewis acid sites (LASs), and contributions from both the Brønsted and Lewis acid sites, respectively. The measured BAS and LAS contributions agree with the acidity properties determined by NH3-TPD (see Table S1), where the Niß catalyst shows the highest amount of LAS (1088 µmol g^-1), followed by NiZ40 (546 µmol g^-

1), NiZ15 (380 µmol g^-1), and finally NiY (82 µmol g^-1). This high LAS amount of the Niß catalyst is attributed to a significant presence of non-framework Si-OH or Al-OH on the surface ¹. Conversely, the NiY catalyst exhibits the highest BAS amount (131 µmol g^-1). All in all, the NiY catalyst presents the highest BAS/LAS ratio followed by the NiZ15, NiZ40,and Niß catalysts.

1440 1480 1520 1560

NiY

Absorbance (a.u.)

Ni

Wavenumber (cm^-1)

NiZ₄₀

NiZ₁₅

L B+L B

Figure S4 Infrared spectra of pyridine adsorption on the fresh catalysts.

10 20 30 40 50 60 70 80 90

Counts (a.u.)

2Theta (^o)

NiY

NiZ₄₀

NiZ₁₅ Ni

*

*

**

* *

* * **

*

* **

* *

* **

* *

* ** *

**

**

**

* *

*

Figure S5 XRD patterns for all fresh catalysts.

The NiY catalyst (Figure S6a) shows a regular octahedral crystal morphology with a particle size of 400 ± 130 nm. The NiZ15 and NiZ40 catalysts(Figs. S6b-c) present similar morphologies of irregular hexagonal crystals with average particle sizes of 210 ± 87 nm and 320 ± 85 nm, respectively. Lastly, the Niß catalyst (Figure S6d) shows spherical nano-crystallites with sizes between 80 and 100 nm that are clustered in agglomerates of about 200–500 nm.

NiY

NiZ15

NiZ40

Ni^

a b

c d

Figure S6 SEM images for the fresh catalysts.

Ni^ NiY

NiZ15

NiZ40

a b

c d

Figure S7 TEM images for the fresh catalysts.

Figure S8 Schematization of the proposed ethylene oligomerization mechanism over the Ni/zeolite catalysts.

0 20 40 60 80 100 120 0.0

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

Normalized CO2/dt

Time TPO (min) 10^-10

Figure S9 Representative CO2 profile from the TG-TPO/MS analysis of the deactivated NiY catalyst after 10 h on stream.

0 20 40 60 80 100 120 140 0 20 40 60 80 100 120 140 0 20 40 60 80 100 120 140

0.0E+00 5.0E-11 1.0E-10 1.5E-10 2.0E-10 2.5E-10 3.0E-10 3.5E-10 4.0E-10

Normalized CO2/dt

Time TPO (min) NiY - 5 h

Time TPO (min) NiY - 10 h

Time TPO (min) NiY - 1 h

0 20 40 60 80 100 120 140 0.0E+00

5.0E-11 1.0E-10 1.5E-10 2.0E-10 2.5E-10 3.0E-10 3.5E-10 4.0E-10

0 20 40 60 80 100 120 140 0 20 40 60 80 100 120 140 Normalized CO2/dt

Time TPO (min) NiZ₄₀ - 1 h

Time TPO (min) NiZ₄₀ - 5 h

Time TPO (min) NiZ₄₀ - 10 h

0 20 40 60 80 100 120 140 0.0E+00

5.0E-11 1.0E-10 1.5E-10 2.0E-10 2.5E-10 3.0E-10 3.5E-10 4.0E-10

0 20 40 60 80 100 120 140 0 20 40 60 80 100 120 140

Normalized CO2/dt

Time TPO (min) NiZ₁₅ - 1 h

Time TPO (min) NiZ₁₅ - 10 h

Time TPO (min) NiZ₁₅ - 5 h

0 20 40 60 80 100 120 140 0 20 40 60 80 100 120 140

0 20 40 60 80 100 120 140 0.0E+00

2.0E-10 4.0E-10 6.0E-10 8.0E-10 1.0E-09

Normalized CO2/dt

Time TPO (min) Ni - 10 h

Time TPO (min) Ni - 5 h

Time TPO (min) Ni - 1 h

Figure S10 Gaussian deconvolutions of the CO2 profiles from the TG-TPO/MS analysis of the deactivated catalyst samples at different times on stream.

0 2 4 6 8 10 0

10 20 30 40 50

0 2 4 6 8 10

0 10 20 30 40 50

0 2 4 6 8 10

0 10 20 30 40 50

SCoke II (gcokeg

-1 e)thylene

TOS (h) a

b

c SCoke I (gcokeg

-1 e)S (ggthyleneTotal cokecoke -1 e)thylene

NiY NiZ₄₀ NiZ₁₅ Ni

Figure S11 Selectivity evolution towards a) total coke, b) coke I, and c) coke II over time on stream for all catalysts.

300 360 420 480 300 360 420 480

300 360 420 480 300 360 420 480

Intensity (a.u.)

m/z

NiY

314 328 342 356 370 384 398 412 426

354 368 382 396 410 424 438 452 466 Intensity (a.u.)

m/z

314 328 342 356 370 384 398

312 326 340 354 368 382 396 410 424 438

NiZ₄₀

c d

Intensity (a.u.)

m/z

NiZ₁₅

314 328 342 356 370 384 398

312 326 340 354 368 382 Intensity (a.u.)

m/z

Ni

396382 410 424 438 452

368354 466 480 494

356 370 384 398 412 426 440 455 468 482

a b

Figure S12 LDI FT-ICR/MS signals in the m/z = 300-500 range for all catalysts deactivated at a time on stream of 5h.

10 20 30 40 50 60 70 80 0

10 20 30 40

10 20 30 40 50 60 70 80

0 10 20 30 40

10 20 30 40 50 60 70 80

0 10 20 30 40

DBE

1 h

5 h

10 h a

b

c

DBEDBE

Carbon number

0.005 0.010 0.050 0.100 0.500 1.000

H/C = 0

0.3 0.6 0.9 1.2 1.5

1.8

H/C = 0

0.3 0.6 0.9 1.2 1.5 1.8

H/C = 0

0.3 0.6 0.9

1.5

1.8

Figure S13 Color-coded isoabundance plots for the total cokes formed at a) 1 h, b) 5 h, and c) 10 h on stream using the NiY catalyst. Darker colors represent higher species concentration while lighter colors represent lower concentrations (in a logarithmic scale).

10 20 30 40 50 60 70 80 0

10 20 30 40

10 20 30 40 50 60 70 80

0 10 20 30 40

10 20 30 40 50 60 70 80

0 10 20 30 40

DBE

1 h

5 h

10 h

H/C = 0 0.3 0.6 0.9 1.2 1.5 1.8

H/C = 0

0.3 0.6

1.2

1.5 1.8

DBEDBE

Carbon number

0.005 0.010 0.050 0.100 0.500 1.000

H/C = 0 0.3 0.6

1.2 1.5

1.8 a

b

c

Figure S14 Color-coded isoabundance plots for the total cokes formed at a) 1 h, b) 5 h, and c) 10 h on stream using the NiZ40 catalyst. Darker colors represent higher species concentration, while lighter colors represent lower concentrations (in a logarithmic scale).

10 20 30 40 50 60 70 80 0

10 20 30 40

10 20 30 40 50 60 70 80

0 10 20 30 40

10 20 30 40 50 60 70 80

0 10 20 30 40

DBE

1 h

5 h

10 h a

b

c

DBEDBE

Carbon number

0.005 0.010 0.050 0.100 0.500 1.000

H/C = 0

0.3 0.6 0.9

1.2 1.5 1.8

H/C = 0 0.3

0.6 0.9

1.2

1.5 1.8

H/C = 0 0.3

0.6

1.2 1.5 1.8

Figure S15 Color-coded isoabundance plots for the total cokes formed at a) 1 h, b) 5 h, and c) 10 h on stream using the NiZ15 catalyst. Darker colors represent higher species concentration while lighter colors represent lower concentrations (in a logarithmic scale).

10 20 30 40 50 60 70 80 0

10 20 30 40

10 20 30 40 50 60 70 80

0 10 20 30 40

10 20 30 40 50 60 70 80

0 10 20 30 40

DBEDBEDBE

Carbon number 1 h

5 h

10 h

0.005 0.010 0.050 0.100 0.500 1.000

H/C = 0 0.3 0.6 0.9

1.2 1.5 1.8

H/C = 0 0.3

0.6 0.9 1.2 1.5 1.8

H/C = 0 0.3 1.2

1.5 1.8 a

b

c

Figure S16 Color-coded isoabundance plots for the total cokes formed at a) 1 h, b) 5 h, and c) 10 h on stream using the Niβ catalyst. Darker colors represent higher species concentration while lighter colors represent lower concentrations (in a logarithmic scale).

20 30 40 50 60 70 80 90 100

FID signal (a.u.)

Retention time (min)

Time on stream, 10 h

Time on stream, 5 h

Time on stream, 1 h

NiZ₄₀ (fresh catalyst)

Figure S17 Chromatograms obtained from the GC analysis of the soluble cokes formed in the NiZ40 catalyst at different times on stream. The signal at the bottom corresponds to the extract obtained from applying the coke extraction protocol on a fresh (non-reacted) NiZ40 catalyst, which was used to discern the GC peaks corresponding to coke species from those which have a zeolitic origin.

Intensity(a.u) Time on stream, 1 h Time on stream, 5 h

Time on stream, 10 h

1H (ppm)

12 11 10 9 8 7 6 5 4 3 2 1 0

Solventpeak Chloroform-d

Figure S18 ¹H NMR spectrum of soluble cokes formed in the NiZ40 catalyst at different times on

Aromatics (H2+H3) Aliphatics (H5-H8) 0

20 40 60 80 100

1 h 5 h 10 h

Normalized area (%)

TOS

a b

H1 H2 H3 H4 H5 H6 H7 H8

0 10 20 30 40

1 h 5 h 10 h

Normalized area (%)

TOS

Figure S19a) Specific type of protons by region and b) total aromatic and aliphatic hydrogens as calculated from integrating the ¹H NMR spectra (Figure S22) for the soluble cokes formed in the NiZ40 catalyst at different times on stream. The designations of the different types of protons are listed in Table S1.

Supplementary Tables

Table S1 Structural assignments for the integration of the soluble coke ¹H NMR spectra as reported by Poveda et al.²

Region (ppm)

Structural assignment

9.0-12.0 H1 Aldehydic and carboxylic hydrogen

7.2-9.0 H2 Aromatic hydrogen linked to aromatic carbons in di- or poly-aromatic rings

6.0-7.2 H3 Aromatic hydrogen linked to mono-aromatic rings 4.5-6.0 H4 Olefinic hydrogen

2.0-4.5 H5 Paraffinic and naphthenic hydrogen (-CH, -CH2, and -CH3) linked to aromatic systems in  position

1.5-2.0 H6 Naphthenic hydrogen (-CH2),  to aromatic systems

1.0-1.5 H7 Paraffinic hydrogen,  to aromatic systems, alkyl termination 0.1-1.0 H8 Paraffinic hydrogen (-CH3),  and more to aromatic systems

Supplementary References

1 L. H. Ong, M. Dömök, R. Olindo, A. C. Van Veen and J. A. Lercher, Microporous Mesoporous Mater., 2012, 164, 9–20.

2 J. C. Poveda and D. R. Molina, J. Pet. Sci. Eng., 2012, 84–85, 1–7.