The present disclosure provides a sound absorbing material. The sound absorbing material comprising MFI-structural-type molecular sieves, the MFI-structural-type molecular sieves comprises frameworks and extra-framework cations, the framework comprising SiO2 and a metal oxide MxOy containing a metal element M, wherein a molar ratio of Si/M is between 220 and 600 in the framework, the metal element M comprises aluminum, and the extra-framework cations are at least one of hydrogen ions, alkali metal ions and alkaline earth metals. The present also provides a method for preparing a sound absorbing material and a speaker box using the sound absorbing material.

The present disclosure provides a sound absorbing material. The sound absorbing material comprising MFI-structural-type molecular sieves, the MFI-structural-type molecular sieves comprises frameworks and extra-framework cations, the framework comprising SiO2 and a metal oxide MxOy containing a metal element M, wherein a molar ratio of Si/M is between 220 and 600 in the framework, the metal element M comprises aluminum, and the extra-framework cations are at least one of hydrogen ions, alkali metal ions and alkaline earth metals. The present also provides a method for preparing a sound absorbing material and a speaker box using the sound absorbing material.

The present disclosure provides a sound absorbing material. The sound absorbing material comprises MEL-structural-type molecular sieves, the MEL-structural-type molecular sieves comprising frameworks and extra-framework cations, the frameworks comprising silica and an oxide MxOy containing an element M which is a non-silicon element; wherein a mass ratio of Si to M in the framework is at least 80, the extra-framework cations comprise at least one of hydrogen ions, alkali metal ions, alkaline earth metal ions and transition metal ions, and a content of the extra-framework cations is between 0.05 wt % and 1.5 wt %.

The present disclosure provides a sound absorbing material. The sound absorbing material comprises MEL-structural-type molecular sieves, the MEL-structural-type molecular sieves comprising frameworks and extra-framework cations, the frameworks comprising silica and an oxide MxOy containing an element M which is a non-silicon element; wherein a mass ratio of Si to M in the framework is at least 80, the extra-framework cations comprise at least one of hydrogen ions, alkali metal ions, alkaline earth metal ions and transition metal ions, and a content of the extra-framework cations is between 0.05 wt % and 1.5 wt %.

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.

According to one or more embodiments presently disclosed, one or more reactant hydrocarbons may be dehydrogenated by a method that includes contacting the one or more reactant hydrocarbons with a catalyst system to dehydrogenate at least a portion of the reactant hydrocarbons. The catalyst system may include a zincosilicate support material that includes an MFI framework type structure incorporating at least silicon and zinc. The catalyst system may further include one or more alkali or alkaline earth metals, and one or more platinum group metals.

The present invention relates to a process for the conversion of 2-aminoethanol to ethane-1,2-diamine and/or linear polyethylenimines of the formula H.sub.2N[CH.sub.2CH.sub.2NH].sub.nCH.sub.2CH.sub.2NH.sub.2 wherein n1 comprising: (i) providing a catalyst comprising a zeolitic material having the MOR framework structure comprising YO.sub.2 and X.sub.2O.sub.3, wherein Y is a tetravalent element and X is a trivalent element, said zeolitic material containing copper as extra-framework ions; (ii) providing a gas stream comprising 2-aminoethanol and ammonia; (iii) contacting the catalyst provided in (i) with the gas stream provided in (ii) for converting 2-aminoethanol to ethane-1,2-diamine and/or linear polyethylenimines.

The present invention relates to a process for the conversion of 2-aminoethanol to ethane-1,2-diamine and/or linear polyethylenimines of the formula H.sub.2N[CH.sub.2CH.sub.2NH].sub.nCH.sub.2CH.sub.2NH.sub.2 wherein n1 comprising: (i) providing a catalyst comprising a zeolitic material having the MOR framework structure comprising YO.sub.2 and X.sub.2O.sub.3, wherein Y is a tetravalent element and X is a trivalent element, said zeolitic material containing copper as extra-framework ions; (ii) providing a gas stream comprising 2-aminoethanol and ammonia; (iii) contacting the catalyst provided in (i) with the gas stream provided in (ii) for converting 2-aminoethanol to ethane-1,2-diamine and/or linear polyethylenimines.

A copper-CHA zeolite catalyst for SCR of NO.sub.x is disclosed.