1. Dieter Freude, Institut für Experimentelle Physik I der Universität Leipzig METU-Center Workshop on Solid State NMR, 1 November 2007 Solid-state NMR studies on microporous and mesoporous materials concerning their structure, acidity and catalytic activity  1 H MAS NMR spectra including TRAPDOR  29 Si MAS NMR  27 Al 3QMAS NMR  27 Al MAS NMR  1 H MAS NMR in the range from 160 K to 790 K

2. 1 H MAS NMR spectra, TRAPDOR H-ZSM-5 activated at 550 °C 44  22 0 246 8 10  / ppm 22 0 468 10  / ppm 44 4.2 ppm 2.9 ppm 2.2 ppm 1.7 ppm 2.2 ppm 1.7 ppm 2.9 ppm with dephasing without dephasing difference spectra 2 Without and with dipolar dephasing by 27 Al high power irradiation and difference spectra are shown from the top to the bottom. The spectra show signals of SiOH groups at framework defects, SiOHAl bridging hydroxyl groups, AlOH group. H-ZSM-5 activated at 900 °C 4.2 ppm

3. 1 H MAS NMR of porous materials

4. 29 Si MAS NMR spectrum of silicalite-1 SiO 2 framework consisting of 24 crystallographic different silicon sites per unit cell (Fyfe 1987).

5. 29 Si MAS NMR

6. 27 Al 3QMAS NMR study of AlPO 4 -14 AlPO 4 -14, 27 Al 3QMAS spectrum (split-t 1 -whole-echo, DFS pulse) measured at 17.6 T with a rotation frequency of 30 kHz. The parameters  CS, iso = 1.3 ppm, C qcc = 2.57 MHz,  = 0.7 for aluminum nuclei at position 1,  CS, iso = 42.9 ppm, C qcc = 1.74 MHz,  = 0.63, for aluminum nuclei at position 2,  CS, iso = 43.5 ppm, C qcc = 4.08 MHz,  = 0.82, for aluminum nuclei at position 3,  CS, iso = 27.1 ppm, C qcc = 5.58 MHz,  = 0.97, for aluminum nuclei at position 5,  CS, iso =  1.3 ppm, C qcc = 2.57 MHz,  = 0.7 were taken from Fernandez et al.

7. 27 Al MAS NMR spectra of a hydrothermally treated zeolite ZSM-5 L = 195 MHz Rot = 15 kHz L = 130 MHz Rot = 10 kHz four-fold coordinated five-fold coordinated six-fold coordinated A signal narrowing by MQMAS or DOR is useless, if the line broadening is dominated by distributions of the chemical shifts.

8. 27 Al MAS NMR

9. Mobility of the Brønsted sites and hydrogen exchange in zeolites OOOOO OOOOOOO AlSi Al  H O NH 4 + OO OO Al H OO OO H OO OO H OO OO H OOO O O OOOOOOO Al  Si Al H O Proton mobility of bridging hydroxyl groups in zeolites H-Y and H-ZSM-5 can be monitored in the temperature range from 160 to 790 K. The full width at half maximum of the 1H MAS NMR spectrum narrows by a factor of 24 for zeolite H-ZSM-5 and a factor of 55 for zeolite 85 H-Y. Activation energies in the range 20-80 kJ mol  have been determined. one-site jumps around one aluminum atom OOOOO OOOOOOO AlSi Al  H O multiple-site jumps along several aluminum atoms

10. Narrowing onset and correlation time 40 °C 120°C 3,2 kHz 17 kHz The correlation time corresponds to the mean residence time of an ammonium ion at an oxygen ring of the framework. 2 H NMR, H-Y: at50 °C  c =5 µs 1 H NMR, H-Y: at 40 °C  c =20 µs 2 H NMR, H-ZSM-5: at 120 °C  c =3,8 µs  =  rigid/2 2 H MAS NMR, deuterated zeolite H-ZSM-5, loaded with 0.33 NH 3 per crossing 1 H MAS NMR, zeolite H-Y, loaded with mit 0.6 NH 3 per cavity The correlation time corresponds to the mean residence time of an ammonium ion at an oxygen ring of the framework.

11. 1D 1 H EXSY (exchange spectroscopy) Evolution time t 1 = 1/4 .  denotes the frequency difference of the exchanging species. MAS frequency should be a multiple of  Two series of measurements should be performed at each temperature: Offset  right of the right signal and offset  left of the left signal. 0 tmtm time  /2 FID t1t1  /2 t2t2 EXSY pulse sequence

12. Result of the EXSY experiment Stack plot of the spectra of zeolite H-Y loaded with 0.35 ammonia molecules per cavity. Mixing times are between t m = 3  s and15 s. Intensities of the signals of ammonium ions and OH groups for zeolite H-Y loaded with 1.5 ammonia molecules per cavity. Measured at 87 °C in the field of 9,4 T. The figure on the top and bottom correspond to offset on the left hand side and right hand side of the signals, respectively.

13. Basis of the data processing diagonal peaks cross peaks dynamic matrix (without spin diffusion):

14. Laser supported 1 H MAS NMR Spectra (at left) and Arrhenius plot (above) of the temperature dependent 1H MAS NMR measurements which were obtained by laser heating. The zeolite sample H-Y was activated at 400 °C.

15. Laser supported high-temperature MAS NMR for time-resolved in situ studies of reaction steps in heterogeneous catalysis: the NMR batch reactor

16. Proton transfer between Brønsted sites and benzene molecules in zeolites H-Y In situ 1 H MAS NMR spectroscopy of the proton transfer between bridging hydroxyl groups and benzene molecules yields temperature dependent exchange rates over more than five orders of magnitude. H-D exchange and NOESY MAS NMR experiments were performed by both conventional and laser heating up to 600 K.

17. Exchange rate as a dynamic measure of Brønsted acidity Arrhenius plot of the H-D and H-H exchange rates for benzene molecules in the zeolites 85 H-Y and 92 H-Y. The values which are marked by blue or red were measured by laser heating or conventional heating, respectively. The variation of the Si/Al ratio in the zeolite H-Y causes a change of the deprotonation energy and can explain the differences of the exchange rate of one order of magnitude in the temperature region of 350  600 K. However, our experimental results are not sufficient to exclude that a variation of the pre- exponential factor caused by steric effects like the existence of non-framework aluminum species is the origin of the different rates of the proton transfer.

18. I acknowledge support from Horst Ernst Clemens Gottert Johanna Kanellopoulos Bernd Knorr Lutz Moschkowitz Dagmar Prager Denis Schneider Deutsche Forschungsgemeinschaft Max-Buchner-Stiftung