The synthesis of TBA-and DPA-VPI-5 has been studied in detail. Optimal synthesis conditions have been established using ternary composition diagrams for TBA-Al203-PzOs and DPA-Al203-PzO. Gel samples at different aging times have been examined using chemical analysis, X-ray diffraction, FT-IR, and solid-state NMR. Two reactions occur between H3P04 and pseudo-boehmite during gel aging. Interaction between the acid and the OH groups linking the pseudo-boehmite layers leads to the formation of an AI-0-P species in which A1 is 6-coordinated. A further reaction between the acid and the AI-O-P species results in the formation of a 4-coordinated A1 species. Because of the different aging conditions, the latter reaction begins much earlier in the TBA system than in the DPA system. The behavior of DPA in the synthesis gel is different from that of TBA. There is evidence that crystallization of VPI-5 proceedsvia a solid-state mechanism, and that nucleation in both systems occurs already during the aging of the gels.

The effects of pore structure on the reaction rates and selectivities in the liquid-phase hydrogenation of 2-ethylanthraquinone over Ni-B amorphous alloy catalysts prepared by the reductant-impregnation method were studied using regular (HMS, MCM-41, and SBA-15) and commercial mesoporous silicas as supports. The composition, particle size, and location of the Ni-B particles were profoundly influenced by the pore structure of the supports. It is found that the location of the Ni-B particles depended on the pore size of the supports, whereas the uniformity of particle size was related to the interaction between the Ni-B particles and the supports. The hydrogenation rate was much faster on Ni-B catalysts with pore diameters exceeding 5 nm than on the narrow-pore catalysts, whereas the selectivity to 2-ethyldihydroanthraquinone, the carbonyl group hydrogenation product, was higher on Ni-B catalysts supported on regular mesoporous silicas. The best activity and selectivity were achieved when using SBA-15 as the support, which is attributable to the formation of more uniform active sites due to the unique pore structure of SBA-15.

Effect of MgAl2O4 on the structure, acidity as well as the catalytic performance of Nb2O5/-Al2O3 catalyst for ethylene oxide hydration was studied using IR, XRD, NH3-TPD, CO2-TPD and catalytic reaction. Modification of Al2O3 support with MgAl2O4 led to an increase in both basicity and mechanical strength of the support. As a result, the density and strength of the acidity of the niobium oxide catalyst supported on the MgAl2O4 modified -Al2O3 reduced in comparison with that supported on the pure -Al2O3. The acidity of 10% Nb2O5/MgAl2O4/-Al2O3 decreased with increasing loading of MgAl2O4. Catalytic test showed that EO conversion decreased monotonously with increasing MgAl2O4 loading, whereas the selectivity to MEG exhibited a maximum of 90.6% at MgAl2O4 loading of 2.23%. In terms of MEG yield, optimal MgAl2O4 loading should be around 2%. Durability test emonstrated that 10% Nb2O5/MgAl2O4/-Al2O3 catalyst exhibited excellent stability within 1000 h time-on-stream.

Graphite oxide (GO) and its derivatives have been studied using 13C and 1H NMR. The 13C NMR lines at 60, 70, and 130 ppm are assigned to C-OH, C-O-C, and>CdC<groups in the bulk of the material, respectively. The>CdC<double bonds are relatively stable, while C-OH groups may condense to form C-O-C (ether) linkages. There are at least two magnetically inequivalent C-OH sites, and the structure does not necessarily possess long-range order. Water molecules interact very strongly with the structure. The results reveal a number of new structural features.

Solid-state 13C NMR spectra of graphite oxide GO. and its derivatives prompt us to propose a new structural model. The spectra of GO treated with KI and the course of the thermal decomposition of GO reveal the presence of epoxide groups, responsible for the oxidating nature of the material. GO is built of aromatic'islands' of variable size which have not been oxidized, and are separated from each other by aliphatic 6-membered rings containing C-OH, epoxide groups and double bonds. The carbon grid is nearly flat; a small degree of warping is caused by the carbons attached to OH groups, which are in a slightly distorted tetrahedral configuration.