Provided is a method for preparing a lower unsaturated fatty acid ester, which comprises carrying out an aldol condensation reaction between dimethoxymethane (DMM) and a lower acid or ester with a molecular formula of R.sub.1CH.sub.2COOR.sub.2 on an acidic molecular sieve catalyst in an inert atmosphere to obtain a lower unsaturated fatty acid or ester(CH.sub.2C(R.sub.1)COOR.sub.2), wherein R.sub.1 and R.sub.2 are groups each independently selected from the group consisting of H and C.sub.1-C.sub.4 saturated alkyl group.

Provided is a method for preparing a lower unsaturated fatty acid ester, which comprises carrying out an aldol condensation reaction between dimethoxymethane (DMM) and a lower acid or ester with a molecular formula of R.sub.1CH.sub.2COOR.sub.2 on an acidic molecular sieve catalyst in an inert atmosphere to obtain a lower unsaturated fatty acid or ester(CH.sub.2C(R.sub.1)COOR.sub.2), wherein R.sub.1 and R.sub.2 are groups each independently selected from the group consisting of H and C.sub.1-C.sub.4 saturated alkyl group.

The present disclosure provides a sound absorbing material. The sound absorbing material comprising a heteroatom zeolite molecular sieve comprising a framework and an extra-framework cation, the framework comprising SiO2 and a metal oxide MxOy comprising a metal element M, wherein the framework has a molar ratio of Si/M between 250 to 500, wherein the M includes Fe, and that the extra-framework cation is at least one of a monovalent copper ion, a monovalent silver ion, a monovalent gold ion, an alkali metal ion or an alkaline earth metal ion. The sound absorbing material provided by the present disclosure, sound absorbing material to have better oxygen adsorption capacity, good waster repellency and stability. When such a sound absorbing material is applied to a speaker box, the speaker box will have better low frequency acoustic performance and better reliability.

The present disclosure provides a sound absorbing material. The sound absorbing material comprising a heteroatom zeolite molecular sieve comprising a framework and an extra-framework cation, the framework comprising SiO2 and a metal oxide MxOy comprising a metal element M, wherein the framework has a molar ratio of Si/M between 250 to 500, wherein the M includes Fe, and that the extra-framework cation is at least one of a monovalent copper ion, a monovalent silver ion, a monovalent gold ion, an alkali metal ion or an alkaline earth metal ion. The sound absorbing material provided by the present disclosure, sound absorbing material to have better oxygen adsorption capacity, good waster repellency and stability. When such a sound absorbing material is applied to a speaker box, the speaker box will have better low frequency acoustic performance and better reliability.

An apparatus is provided for treatment of process gas formed during nitric acid production by catalytic oxidation of NH.sub.3. The apparatus includes a reactor, a first catalyst bed for N.sub.2O decomposition, an absorption tower to react the NO.sub.x formed with an absorption medium downstream of the first catalyst bed, a device for adding NH.sub.3 added to tailgas entering the second catalyst bed, and a second catalyst bed for NO.sub.x reduction and further decrease in N.sub.2O in the tailgas exiting the absorption tower. The second catalyst bed contains at least one iron-loaded zeolite catalyst. N.sub.2O removal in the first catalyst bed is limited such that the process gas exiting the first catalyst bed exhibits a N.sub.2O content of >100 ppmv and a molar N.sub.2O/NO.sub.x ratio of >0.25. Treated gas exiting the second catalyst bed has a NO.sub.x concentration of <40 ppmv and a N.sub.2O concentration of <200 ppmv.

Provided herein is a catalytic article including a catalytic coating disposed on a substrate, wherein the catalytic coating comprises a bottom coating on the substrate and a top coating layer on the bottom coating layer, one such coating layer containing a platinum group metal on a refractory metal oxide support and the other such coating layer containing a ceria-containing molecular sieve. Such catalytic articles are effective toward treating exhaust gas streams of internal combustion engines and exhibit outstanding resistance to sulfur.

The present invention relates to a catalyst composition comprising a modified crystalline aluminosilicate of the Framework Type FER having Si/Al framework molar/ratio greater than 20 characterized in that in said modified crystalline aluminosilicate the ratio between the strong acid sites and the weak acid sites, S/W, is lower than 1.0 and having the extra framework aluminum (EFAL) content lowered to less than 10 wt % preferably 5 wt % even more preferably less than 2 wt % measured by 27Al MAS NMR. The present invention further relates to a process for producing olefins from alcohols in presence of said catalyst composition.

The present invention relates to a catalyst composition comprising a modified crystalline aluminosilicate of the Framework Type FER having Si/Al framework molar/ratio greater than 20 characterized in that in said modified crystalline aluminosilicate the ratio between the strong acid sites and the weak acid sites, S/W, is lower than 1.0 and having the extra framework aluminum (EFAL) content lowered to less than 10 wt % preferably 5 wt % even more preferably less than 2 wt % measured by 27Al MAS NMR. The present invention further relates to a process for producing olefins from alcohols in presence of said catalyst composition.

A catalyst for the carbonylation of dimethyl ether to methyl acetate. The catalyst comprises a zeolite, such as a mordenite zeolite, at least one Group IB metal, such as copper, and/or at least one Group VIII metal, such as iron, and at least one Group IIB metal, such as zinc. Such a catalyst with combined metals provides enhanced catalytic activity, improved stability, and improved selectivity to methyl acetate, and does not require a halogen promoter, as compared to a metal-free or copper only zeolite.

Provided are a structured catalyst for CO shift or reverse shift that can realize a long life time by suppressing the decline in function, a method for producing the same, a CO shift or reverse shift reactor, a method for producing carbon dioxide and hydrogen, and a method for producing carbon monoxide and water. The structured catalyst for CO shift or reverse shift (1) includes a support (10) of a porous structure composed of a zeolite-type compound, and at least one CO shift or reverse shift catalytic substance (20) present in the support (10), the support (10) has channels (11) connecting with each other, and the CO shift or reverse shift catalytic substance (20) is present at least in the channels (11) of the support (10).