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.

Modified crystalline zeolite materials have a zeolite framework with both tetra-coordinate Lewis aluminum single sites and Brønsted aluminum sites. The tetra-coordinate Lewis aluminum single sites include aluminum atoms covalently bonded to a variable group and to two oxygen atoms and further coordinated to a third oxygen atom. The variable group may be alkyl, hydride, or hydroxyl. Methods for incorporating tetra-coordinate Lewis aluminum single sites into a crystalline zeolite material include contacting the crystalline zeolite material with a dialkylaluminum hydride R.sub.2AlH, where each R is alkyl, to react the dialkylaluminum hydride with the zeolite framework and form tetra-coordinate alkyl aluminum single sites. Heating the alkyl-aluminum zeolite induces β-hydride elimination of the alkyl groups, whereby tetra-coordinate aluminum hydride single sites are formed. By oxidizing the hydride-aluminum zeolite, at least a portion of the tetra-coordinate aluminum hydride single sites are converted to tetra-coordinate aluminum hydroxide single sites.

Modified crystalline zeolite materials have a zeolite framework with both tetra-coordinate Lewis aluminum single sites and Brønsted aluminum sites. The tetra-coordinate Lewis aluminum single sites include aluminum atoms covalently bonded to a variable group and to two oxygen atoms and further coordinated to a third oxygen atom. The variable group may be alkyl, hydride, or hydroxyl. Methods for incorporating tetra-coordinate Lewis aluminum single sites into a crystalline zeolite material include contacting the crystalline zeolite material with a dialkylaluminum hydride R.sub.2AlH, where each R is alkyl, to react the dialkylaluminum hydride with the zeolite framework and form tetra-coordinate alkyl aluminum single sites. Heating the alkyl-aluminum zeolite induces β-hydride elimination of the alkyl groups, whereby tetra-coordinate aluminum hydride single sites are formed. By oxidizing the hydride-aluminum zeolite, at least a portion of the tetra-coordinate aluminum hydride single sites are converted to tetra-coordinate aluminum hydroxide single sites.

A method for fluid catalytic cracking (FCC) of petroleum oil feedstock includes reacting the petroleum oil feedstock with a catalyst mixture in a reaction zone of an FCC unit to obtain a product stream including desulfurized hydrocarbon product, unreacted petroleum oil feedstock, and spent catalyst. During the reacting a process control system develops a process model based on data collected during the reacting, the process model characterizing a relationship among the feed rate of the base cracking catalyst, the feed rate of the FCC additive, the operating conditions, the composition of the product stream, and emissions from the reaction; and one or more of (i) a target feed rate of the base cracking catalyst, (ii) a target feed rate of the FCC additive, and (iii) one or more target operating conditions of the reaction in the reaction zone to reduce the emissions from the FCC unit and to increase a yield of the desulfurized hydrocarbon product in the product stream are determined.

A method for preparing a zeolite catalyst for catalytic cracking of hydrocarbons to produce propylene is provided, which specifically includes steps of mixing a silicon source, a templating agent, an aluminium source, and a solvent to form a zeolite precursor solution, which is then subjected to hydrothermal crystallization, washing, drying, and calcination to obtain a zeolite precursor; ion-exchanging the zeolite precursor with ammonium ions, followed by drying and calcination; and loading aluminum onto the ion-exchanged zeolite precursor as a carrier via incipient-wetness impregnation by using an aluminium-containing solution, followed by drying and calcination. Zeolite catalysts prepared by the method and use of the catalysts in catalytic cracking of hydrocarbons to produce propylene are also provided.

Processes for converting one or more C.sub.1-C.sub.5 linear or branched alcohols to one or more C.sub.2-C.sub.5 olefins are provided. In one exemplary embodiment, the process can be a single stage process for the direct conversion of C.sub.1-C.sub.5 alcohols to olefinic mixtures (e.g., C.sub.2-C.sub.5) carried out in a reactor using a catalyst that includes zeolite doped with boron and phosphor. Systems for carrying out these processes are also provided.

A bifunctional catalyst for example for conversion of oxygenates, the bifunctional catalyst comprising zeolite, alumina binder, Zn and P, wherein Zn is present at least partly as ZnAl.sub.2O.sub.4.

A bifunctional catalyst for example for conversion of oxygenates, the bifunctional catalyst comprising zeolite, alumina binder, Zn and P, wherein Zn is present at least partly as ZnAl.sub.2O.sub.4.

Disclosed herein are modified zeolites and methods for making modified zeolites. In one or more embodiments disclosed herein, a modified zeolite may include a microporous framework comprising a plurality of micropores having diameters of less than or equal to 2 nm. The microporous framework may include at least silicon atoms and oxygen atoms. The modified zeolite may further include organometallic moieties each bonded to bridging oxygen atoms. The organometallic moieties may include a titanium atom. The titanium atom may be bonded to a bridging oxygen atom, and the bridging oxygen atom may bridge the titanium atom of the organometallic moiety and a silicon atom of the microporous framework.

To provide a method for producing olefins having the carbon atom number of 2 to 3 with a high yield. A method for producing olefins including following steps (1) and (2): step (1): heating a polyolefin plastic to obtain a decomposed product (pyrolysis step); and step (2): causing the decomposed product obtained at the step (1) to contact with an MFI zeolite containing sodium atoms in the range of 0.10% by mass to 0.30% by mass to obtain catalytically cracked products containing olefins (catalytic cracking step).