The present disclosure relates to a molecular sieve, preparation thereof and acoustic absorption material and speaker containing the same. The molecular sieve having an MFI-structure, comprising a framework and an off-framework cation, wherein the framework comprises SiO.sub.2 and a metal oxide M.sub.xO.sub.y with M comprising boron, gallium or aluminium; the off-framework cation is at least one of hydrogen ion, alkali metal ion and alkaline earth metal ion. The molecular herein can effectively prevent the failure of the molecular sieve and improve the performance stability of the speaker.

A small pore size synthetic zeolite having a degree of crystallinity of at least 80% and comprising at least 0.01 wt % based on the weight of the zeolite of at least one catalytic metal selected from the group consisting of Ru, Rh, Pd, Ag, Os, Ir, Pt, Au, Mo, W, Re, Co, Ni, Zn, Cr, Mn, Ce, Ga and combinations thereof, wherein at least 80% of the catalytic metal is encapsulated in the zeolite, wherein if the zeolite is an aluminosilicate it has a SiO.sub.2:Al.sub.2O.sub.3 molar ratio of greater than 6:1.

The present invention relates to a continuous process for preparing a zeolitic material comprising (i) preparing a mixture comprising a source of YO.sub.2, optionally a source of X.sub.2O.sub.3, and a liquid solvent system; (ii) continuously feeding the mixture prepared in (i) into a continuous flow reactor at a liquid hourly space velocity in the range of from 0.3 to 20 h.sup.1 for a duration of at least 1 h; and (iii) crystallizing the zeolitic material from the mixture in the continuous flow reactor, wherein the mixture is heated to a temperature in the range of from 100 to 300 C.; wherein the volume of the continuous flow reactor is in the range of from 150 cm.sup.3 to 75 m.sup.3, as well as to zeolitic materials which may be obtained according to the inventive process and to their use.

A particulate material and a process for the production thereof are provided, which particulate material comprises zeolitic particles having a crystalline structure, which contain as the main component a zeolite material having a zeolitic framework structure formed from Si, O and optionally Al, and/or a zeolite-like material having a zeolitic framework structure which is formed not only from Si, O and optionally Al, wherein the zeolitic particles are in the form of essentially spherical particles with nanometer dimensions.

Catalytic compositions and sequential catalytic methods are generally described. In some embodiments, a composition comprises a first catalyst comprising a Cu-modified zeolite, and a second catalyst capable of a coupling reaction between (a) an intermediate resulting from a reaction of a reactant at the first catalyst, and (b) a co-reagent, wherein a rate of diffusion of the co-reagent within one or more cages and/or pores of the first catalyst is lower than a rate of diffusion of the intermediate within the one or more cages and/or pores of the first catalyst.

Catalytic compositions and sequential catalytic methods are generally described. In some embodiments, a composition comprises a first catalyst comprising a Cu-modified zeolite, and a second catalyst capable of a coupling reaction between (a) an intermediate resulting from a reaction of a reactant at the first catalyst, and (b) a co-reagent, wherein a rate of diffusion of the co-reagent within one or more cages and/or pores of the first catalyst is lower than a rate of diffusion of the intermediate within the one or more cages and/or pores of the first catalyst.

The present invention relates to a process for preparing at least one sheet silicate comprising Ga and/or Zn, and based thereon, a framework silicate, preferably of the RRO structure type, to the sheet silicate and framework silicate themselves and to the uses of the silicates, especially of the framework silicate, preferably as catalysts.

The present invention relates to a process for preparing at least one sheet silicate comprising Ga and/or Zn, and based thereon, a framework silicate, preferably of the RRO structure type, to the sheet silicate and framework silicate themselves and to the uses of the silicates, especially of the framework silicate, preferably as catalysts.

The present invention relates to a catalyst comprising a macroporous noble metal-containing zeolite material and a porous SiO.sub.2-containing binder, wherein the catalyst has a proportion of micropores of more than 70%, based on the total pore volume of the catalyst. The invention is additionally directed to a process for preparing the catalyst and to the use of the catalyst as an oxidation catalyst.

A novel synthetic crystalline molecular sieve designated as SSZ-109 is disclosed. SSZ-109 is synthesized using a structure directing agent comprising one or more of N,N,N,N-tetramethyl-N,N-diisobutylhexane-1,6-diammonium cations, N,N,N,N-tetramethyl-N,N-dineopentylhexane-1,6-diammonium cations, and N,N,N,N-tetramethyl-N-isobutyl-N-neopentylhexane-1,6-diammonium cations.