Lewis acid site — Puncak serapan FTIR dan tugasan
Ini adalah nombor gelombang FTIR ciri di mana Lewis acid site cenderung menyerap, disusun dari literatur yang diterbitkan dan disusun berdasarkan bukti sokongan. Setiap tugasan dapat dikesan ke sumber (DOI) dan disahkan silang terhadap 130,000+ spektrum rujukan dan graf pengetahuan kami.
Backed by 8 cited sources
Jawapan pantas
Lewis acid site biasanya ditetapkan dengan mencari kelompok berulang puncak ciri dan bukan satu nombor tepat buku teks. Jadual di bawah menunjukkan di mana literatur paling kerap meletakkan kumpulan ini dalam FTIR, yang disusun mengikut bukti terkumpul.
Puncak FTIR ciri untuk Lewis acid site
| Nombor gelombang (cm⁻¹) | Fakta sokongan | Sumber dipetik | Keyakinan tertinggi |
|---|---|---|---|
| 1445 | 4 | 3 | 1.0 |
| 1545 | 4 | 2 | 1.0 |
| 1455 | 3 | 0 | 1.0 |
| 1540 | 2 | 2 | 1.0 |
| 1605 | 2 | 2 | 1.0 |
| 1490 | 2 | 1 | 1.0 |
| 1449 | 1 | 1 | 1.0 |
| 1393 | 1 | 1 | 1.0 |
| 1442 | 1 | 1 | 1.0 |
| 2306 | 1 | 1 | 1.0 |
| 1575 | 1 | 1 | 1.0 |
| 1650 | 1 | 1 | 1.0 |
| 2275 | 1 | 1 | 1.0 |
| 2272 | 1 | 1 | 1.0 |
| 2295 | 1 | 1 | 1.0 |
| 1438 | 1 | 1 | 1.0 |
| 1495 | 1 | 1 | 1.0 |
| 2166 | 1 | 1 | 1.0 |
| 1456 | 1 | 1 | 1.0 |
| 1444 | 1 | 1 | 1.0 |
| 1454 | 1 | 1 | 1.0 |
| 1614 | 1 | 1 | 1.0 |
| 1453 | 1 | 1 | 1.0 |
| 1642 | 1 | 1 | 1.0 |
| 1635 | 1 | 1 | 1.0 |
| 2322 | 1 | 1 | 1.0 |
| 1606 | 1 | 1 | 1.0 |
| 1489 | 1 | 1 | 1.0 |
| 3733 | 1 | 1 | 1.0 |
| 3786 | 1 | 1 | 1.0 |
Menunjukkan 30 puncak terbaik disokong daripada 45 jumlah untuk Lewis acid site.
Logik spektrum
Tugasan kumpulan berfungsi menjadi lebih yakin apabila beberapa jalur yang dijangkakan muncul bersama. Gunakan halaman ini untuk mencari puncak yang paling disokong, kemudian sahkan bahawa sampel yang sama menunjukkan corak yang koheren dan bukannya satu hit terpencil.
Penggunaan dunia sebenar
Halaman-halaman ini berguna untuk analisis bahan yang tidak diketahui, penjelasan puncak dalam laporan, penyelesaian masalah polimer, dan mengesahkan sama ada keluarga bahan calon adalah boleh dipercayai secara kimia.
Kesilapan biasa
- Menggunakan satu halaman kumpulan berfungsi sebagai keputusan bahan lengkap tanpa memeriksa spektrum yang lain.
- Dengan menganggap jalur yang paling kuat sentiasa menjadi yang paling diagnostik.
- Melupakan bahawa pemprosesan, bahan tambahan, penuaan, dan campuran boleh mengalihkan atau melebarkan puncak yang dijangkakan.
Nasihat pengesahan
Gunakan DSC, GC-MS, atau TGA apabila beberapa keluarga bahan berkongsi jalur yang serupa atau apabila kesan campuran menyebabkan tugasan FTIR tidak pasti.
Literatur di sebalik penetapan ini
-
1605 cm⁻¹ keyakinan 1.0
“remains above 473 K can most likely be attributed to the as- (cid:228) to 1288 while the peak at 1605 shifts to 1588 (NH 3) coordinated to Lewis acid sites that are still adsorbed on Both of these peaks remain, even as the temperature is in”
Pena 等 - 2004 - Identification of surface species on titania-suppo DOI: 10.1021/jp0313122 -
1700 cm⁻¹ keyakinan 1.0
“Both catalysts showed several cm-1, Brönsted and Lewis acid sites due to the interaction between iridabsorption bands at 1700, 1680, 1650, and 1640 which are ium and lattice defects or extra-lattice oxygen.”
IR study of iridium bonded to perturbed silanol groups of Pt-HZSM5 for n-pentane isomerization DOI: 10.1016/j.apcata.2011.12.039 -
1490 cm⁻¹ keyakinan 1.0
“The spectra also show a band at 1490 150 common to a vibration mode of pyridine coordinated to the catalysts' Lewis acid sites and”
TiO2 Catalyzed Dihydroxyacetone (DHA) Conversion in Water: Evidence That This Model Reaction Probes Basicity in Addition to Acidity DOI: 10.3390/molecules27238172 -
1540 cm⁻¹ keyakinan 1.0
“The typical bands resulting from pyridine adsorbed on Brønsted acid sites sites (PyH+) are observed around 1540 cm-1, while the bands from pyridine interacting with Lewis (PyH+ cm-1, ) are observed around 1540 while the bands from pyridine”
Bellmann 等 - 2020 - Determining the Location of Co2+ in Zeolites by UV DOI: 10.3390/catal10010123 -
3786 cm⁻¹ keyakinan 1.0
“The shouldering near 3786 and the band at are assigned to CO adsorbed on strong cm(cid:1)1 cm(cid:1)1 3770 Lewis acid sites.”
Benkhaled 等 - 2006 - Synthesis of highly dispersed palladium alumina su DOI: 10.1016/j.apcata.2006.06.011 -
1489 cm⁻¹ keyakinan 1.0
“cm-1) contained both bands of pyridine coordinated to Lewis sites (1608, 1489 and 1446 and pyridinium cations formed by reaction of pyridine with Brønsted sites (1640, 1547 and 1489 cm-1).”
Unravelling water effects on solid acidic catalysts: Case study of TiO 2 /SiO 2 for dehydration of isobutanol DOI: 10.1016/j.jcat.2016.12.007 -
2322 cm⁻¹ keyakinan 1.0
“The concentration of Brønsted and Lewis sites were obtained cm-1 365 from the integral intensities of the IR bands of adsorbed CD 3CN at 2296 and 2322 cm-1, 366 respectively, by using the extinction factor coefficients reported in Section 2”
New synthesis routes and catalytic applications of ferrierite crystals. Part 1: 1,8-Diaminooctane as a new OSDA DOI: 10.1016/j.micromeso.2019.109987 -
1635 cm⁻¹ keyakinan 1.0
“In contrast, the ratio of the acid were nated to the Lewis acid sites and the bands at 1635 and 1545 Brønsted Brønsted sites concentration to the total and Lewis acid sites concenattributed to pyridine bounded to the acid sites.”
Fedyna 等 - 2020 - Composite of PtAlSBA-15+zeolite catalyst for the DOI: 10.1016/j.micromeso.2020.110366
Lihat Lewis acid site dalam spektrum anda sendiri
Muat naik spektrum FTIR anda dan dapatkan laporan tafsiran penuh — tugasan puncak dengan petikan literatur, padanan perpustakaan, dan analisis berasaskan literatur — dalam beberapa saat.