Table 2. Formation Energies (ΔE) of π Complex (Ads-C4), Carbenium-Ion-like Transition State (TS-C4), and Surface tert-Butoxy Species (Alkoxy-C4) with Respect to Free Model and Gas-Phase Isobutene (all energies are in kJ/mol)a.
| Ads-C4 |
TS-C4 |
Alkxoy-C4 |
activation
barriers |
|||||
|---|---|---|---|---|---|---|---|---|
| zeolite modelb | ΔE | ΔE(D) | ΔE | ΔE(D) | ΔE | ΔE(D) | ΔE⧧total | ΔE⧧total – ΔE⧧(D) |
| FAU-47 | –73 | –40 | –42 | –50 | –73 | –60 | 30 | 40 |
| FAU-7 | –70 | –43 | –27 | –52 | –76 | –63 | 43 | 52 |
| FAU-2.4 | –69 | –44 | –2 | –55 | –34 | –64 | 67 | 78 |
| FAU-Fe | –68 | –40 | –24 | –47 | –87 | –59 | 44 | 51 |
| FAU-Ga | –71 | –41 | –35 | –49 | –81 | –62 | 36 | 44 |
| FAU-SAPO | –68 | –42 | –20 | –52 | –71 | –61 | 49 | 59 |
| FAU-Na | –75 | –42 | –49 | –52 | –66 | –66 | 27 | 37 |
| MFI | –97 | –79 | –62 | –70 | –86 | –77 | 35 | 26 |
| CHA | –97 | –70 | –24 | –98 | –27 | –101 | 72 | 101 |
a
The corresponding dispersion components of ΔE are indicated as ΔE(D). Activation barriers (ΔE≠total) and respective dispersion-uncorrected values (ΔE≠total – ΔE≠(D)) are listed separately.
b
As the estimated energy barriers in EFAl-containing models are even lower than 5 kJ/mol (Table S3), we ignore these models here to minimize the methodological error from DFT calculations.