Crystalline zeolites having a FER framework type wherein the crystallites have a dimension in the c-axis of about 500 nanometers (nm) or less, a method for their preparation and a process for the co-production of acetic acid and dimethyl ether comprising the step of contacting methyl acetate and methanol in the presence of catalysts comprising the crystalline zeolites.

SCR-active molecular-sieve based catalysts with improved low-temperature performance are made by heating a molecular-sieve in a non-oxidizing atmosphere with steam (hydrothermal treatment), or in a reducing atmosphere without steam (thermal treatment), at a temperature in the range of 600-900? C. for a time period from 5 minutes to two hours. The resulting SCR-active iron-containing molecular sieves exhibit a selective catalytic reduction of nitrogen oxides with NH.sub.3 or urea at 250? C. that is at least 50% greater than if the iron-containing molecular-sieve were calcined at 500? C. for two hours without performing the hydrothermal or thermal treatment.

SCR-active molecular-sieve based catalysts with improved low-temperature performance are made by heating a molecular-sieve in a non-oxidizing atmosphere with steam (hydrothermal treatment), or in a reducing atmosphere without steam (thermal treatment), at a temperature in the range of 600-900? C. for a time period from 5 minutes to two hours. The resulting SCR-active iron-containing molecular sieves exhibit a selective catalytic reduction of nitrogen oxides with NH.sub.3 or urea at 250? C. that is at least 50% greater than if the iron-containing molecular-sieve were calcined at 500? C. for two hours without performing the hydrothermal or thermal treatment.

Disclosed are a tandem catalyst for synthesizing methyl acetate from carbon dioxide, a method for preparing the same, and a method for preparing methyl acetate using the same. The tandem catalyst of the present invention includes a first catalyst having a core-shell structure including a composite metal oxide core and a silica shell surrounding a surface of the composite metal oxide core, and a second catalyst including nano-ferrierite (N-FER) zeolite.

A process for the co-production of acetic acid and dimethyl ether by contacting methyl acetate and methanol in the presence of catalysts comprising crystalline zeolites having a FER framework type which crystallites have a dimension in the c-axis of about 500 nm or less and a ratio of the c-axis:b-axis dimension of 5:1 or greater and a method for preparation of the zeolites utilizing piperazines.

A method to remove silica from a silica containing material characterized in that it comprises (i) contacting said silica containing material with a first metal ion carbonate, to obtain a first composition, and (ii) heating said first composition in a vessel at a temperature sufficient to increase the pressure above the atmospheric pressure in said vessel or at a pressure of at least 2 bara and at a temperature of at least 80 C., preferably 100 C. wherein said pressure is preferably autogeneously generated, wherein the total amount of water of said first composition originating from (a) the silica containing material and from (b) the first metal ion carbonate is greater or equal to 4 mol of water per mol of metal ion carbonate, and wherein the first composition obtained at step (i) is not a suspension in water and is under solid state at standard temperature and pressure (STP), before the performance of step (ii) and wherein said silica containing material is a zeolite

A mesoporous zeolitic material possessing an ordered mono-dimensional (1D) or two-dimensional (2D) network of micropores (ie pores<2 nm in diameter) containing mesopores (pores with diameters in the range 2-50 nm) connected to the microporores, the mesopores being characterized by an aspect ratio (length to width) higher than 2, a ratio of the volume of the intracrystalline mesopores to the volume of the micropores in the range 0.1 to 2 and an orientation of the mesopores in the direction of the micropores.

A mesoporous zeolitic material possessing an ordered mono-dimensional (1D) or two-dimensional (2D) network of micropores (ie pores<2 nm in diameter) containing mesopores (pores with diameters in the range 2-50 nm) connected to the microporores, the mesopores being characterized by an aspect ratio (length to width) higher than 2, a ratio of the volume of the intracrystalline mesopores to the volume of the micropores in the range 0.1 to 2 and an orientation of the mesopores in the direction of the micropores.

Provided is a method of encapsulating a metal in a zeolite. The method comprises inserting a metal precursor into a parent zeolite, and then converting the parent zeolite to a zeolite having a higher framework density than the parent zeolite. The conversion is achieved without the need of an organic structure directing agent.

Provided is a method of encapsulating a metal in a zeolite. The method comprises inserting a metal precursor into a parent zeolite, and then converting the parent zeolite to a zeolite having a higher framework density than the parent zeolite. The conversion is achieved without the need of an organic structure directing agent.