A novel process and a novel catalyst for the production of light olefins. 1-butene is cracked in the presence of an acid- or base-modified silicalite-1 catalyst bed, wherein the modified silicalite-1 has a Si/Al ratio of greater than 1000. The modification procedures described herein increase the selectivity of the silicalite-1 catalyst toward light olefins such as ethylene and propylene. The catalytic cracking of 1-butene may be carried out in a fixed bed reactor or a fluidized bed reactor.

A novel process and a novel catalyst for the production of light olefins. 1-butene is cracked in the presence of an acid- or base-modified silicalite-1 catalyst bed, wherein the modified silicalite-1 has a SiAl ratio of greater than 1000. The modification procedures described herein increase the selectivity of the silicalite-1 catalyst toward light olefins such as ethylene and propylene. The catalytic cracking of 1-butene may be carried out in a fixed bed reactor or a fluidized bed reactor.

Disclosed is a catalyst for preparing isobutene by dissociation of methyl tert-butyl ether, the catalyst comprising amorphous silica alumina and a silicalite-1 molecular sieve, wherein the total IR acid amount of weak acids in the catalyst is in a range from 0.020 to 0.080 mmol/g, and the ratio of B acid/L acid of the weak acids is in a range from 2.5:1 to 4.0:1. Also provided is a method of preparing the catalyst and the use thereof. The catalyst has a high selectivity with respect to isobutene, and high conversion of methyl tert-butyl ether, and can also effectively inhibit formation of the by-product dimethyl ether.

A silicate-coated MFI-type zeolite is obtained by coating an MFI-type zeolite with a silicate, and a peak area ratio b/a of a peak b at 2=8.4 to 9.7 to a peak a at 2=7.0 to 8.4 in an X-ray diffraction spectrum is 1 or more, and a pKa value measured by a Hammett indicator is +3.3 or more.

A novel process and a novel catalyst for the production of light olefins. 1-butene is cracked in the presence of an acid- or base-modified silicalite-1 catalyst bed, wherein the modified silicalite-1 has a Si/Al ratio of greater than 1000. The modification procedures described herein increase the selectivity of the silicalite-1 catalyst toward light olefins such as ethylene and propylene. The catalytic cracking of 1-butene may be carried out in a fixed bed reactor or a fluidized bed reactor.

Described is a process for the production of a zeolitic material having an MFI, MEL, and/or MWW-type framework structure comprising YO.sub.2 and X.sub.2O.sub.3. The process comprises (1) preparing a mixture comprising one or more sources for YO.sub.2, one or more sources for X.sub.2O.sub.3, and one or more solvents; (2) crystallizing the mixture obtained in step (1) to obtain a zeolitic material having an MFI, MEL and/or MWW-type framework structure; and (3) impregnating the zeolitic material obtained in step (2) with one or more elements selected from the group of alkaline earth metals. Y is a tetravalent element, and X is a trivalent element. The mixture crystallized in step (2) contains 3 wt.-% or less of one or more elements M based on 100 wt-% of YO.sub.2, wherein M stands for sodium.

Embodiments of processes for producing propylene utilize a dual catalyst system comprising a mesoporous silica catalyst impregnated with metal oxide and a mordenite framework inverted (MFI) structured silica catalyst downstream of the mesoporous silica catalyst, where the mesoporous silica catalyst includes a pore size distribution of at least 2.5 nm to 40 nm and a total pore volume of at least 0.600 cm.sup.3/g, and the MFI structured silica catalyst has a total acidity of 0.001 mmol/g to 0.1 mmol/g. The propylene is produced from the butene stream via metathesis by contacting the mesoporous silica catalyst and subsequent cracking by contacting the MFI structured silica catalyst.

Embodiments of processes for producing propylene utilize a dual catalyst system comprising a mesoporous silica catalyst impregnated with metal oxide and a mordenite framework inverted (MFI) structured silica catalyst downstream of the mesoporous silica catalyst, where the mesoporous silica catalyst includes a pore size distribution of at least 2.5 nm to 40 nm and a total pore volume of at least 0.600 cm.sup.3/g, and the MFI structured silica catalyst has a total acidity of 0.001 mmol/g to 0.1 mmol/g. The propylene is produced from the butene stream via metathesis by contacting the mesoporous silica catalyst and subsequent cracking by contacting the MFI structured silica catalyst.