The present invention relates to novel catalysts for oxidative esterification, by means of which, for example, (meth)acrolein can be converted to methyl (meth)acrylate. The catalysts of the invention are especially notable for high mechanical and chemical stability even over very long periods. This especially relates to an improvement in the catalyst service life, activity and selectivity over prior art catalysts which lose activity and/or selectivity relatively quickly in continuous operation in media having even a small water content.

The present invention relates to novel catalysts for oxidative esterification, by means of which, for example, (meth)acrolein can be converted to methyl (meth)acrylate. The catalysts of the invention are especially notable for high mechanical and chemical stability even over very long periods. This especially relates to an improvement in the catalyst service life, activity and selectivity over prior art catalysts which lose activity and/or selectivity relatively quickly in continuous operation in media having even a small water content.

Process for preparing a catalyst composition containing a modified crystalline aluminosilicate and a binder, wherein the catalyst composition comprises from 5 to 95% by weight of crystalline aluminosilicate as based on the total weight of the catalyst composition, the process being remarkable in that it comprises a step of steaming said crystalline aluminosilicate: at a temperature ranging from 100 C. to 380 C.; under a gas phase atmosphere containing from 5 wt % to 100 wt % of steam; at a pressure ranging from 2 to 200 bars; at a partial pressure of H.sub.2O ranging from 2 to 200 bars; and said steaming being performed during at least 30 min and up to 144 h;
and in that the process also comprises a step of shaping, or of extruding, the crystalline aluminosilicate with a binder, wherein the binder is selected to comprise at least 85 wt % of silica as based on the total weight of the binder, and less than 1000 ppm by weight as based on the total weight of the binder of aluminium, gallium, boron, iron and/or chromium.

Process for preparing a catalyst composition containing a modified crystalline aluminosilicate and a binder, wherein the catalyst composition comprises from 5 to 95% by weight of crystalline aluminosilicate as based on the total weight of the catalyst composition, the process being remarkable in that it comprises a step of steaming said crystalline aluminosilicate: at a temperature ranging from 100 C. to 380 C.; under a gas phase atmosphere containing from 5 wt % to 100 wt % of steam; at a pressure ranging from 2 to 200 bars; at a partial pressure of H.sub.2O ranging from 2 to 200 bars; and said steaming being performed during at least 30 min and up to 144 h;
and in that the process also comprises a step of shaping, or of extruding, the crystalline aluminosilicate with a binder, wherein the binder is selected to comprise at least 85 wt % of silica as based on the total weight of the binder, and less than 1000 ppm by weight as based on the total weight of the binder of aluminium, gallium, boron, iron and/or chromium.

Processes for calcining a catalyst. The process can include subjecting a synthesized catalyst that includes Pt disposed on a support to an initial calcination that includes exposing the catalyst to a first reducing gas or a first oxidizing gas to produce an initial calcined catalyst. The process can optionally include subjecting the initial calcined. catalyst to a cycle calcination that includes exposing the initial calcined catalyst to a second reducing gas and a second oxidizing gas to produce a cycle calcined catalyst. The process can optionally include subjecting the initial or the cycle calcined catalyst to a final calcination that includes exposing the initial or the cycle calcined catalyst to a third reducing gas or a third oxidizing gas. At least one of the cycle and the final calcination can be carried out. A calcined catalyst can be obtained at the end of the cycle or the final calcination.

Processes for calcining a catalyst. The process can include subjecting a synthesized catalyst that includes Pt disposed on a support to an initial calcination that includes exposing the catalyst to a first reducing gas or a first oxidizing gas to produce an initial calcined catalyst. The process can optionally include subjecting the initial calcined. catalyst to a cycle calcination that includes exposing the initial calcined catalyst to a second reducing gas and a second oxidizing gas to produce a cycle calcined catalyst. The process can optionally include subjecting the initial or the cycle calcined catalyst to a final calcination that includes exposing the initial or the cycle calcined catalyst to a third reducing gas or a third oxidizing gas. At least one of the cycle and the final calcination can be carried out. A calcined catalyst can be obtained at the end of the cycle or the final calcination.

The present invention relates to a method for preparing a CaMgAl mixed oxide comprising the steps: a) providing a modified layered double hydroxide of the formula (I) wherein in formula (I) 0<x<0.9; b is from 0 to 10, preferably 1 to 10; c is from 0 to 10, preferably 1 to 10 and the AMO-solvent is an organic solvent miscible with water; b) calcining the modified layered double hydroxide; c) reacting the calcined modified layered double hydroxide with a calcium salt in the presence of an (a) organic acid; and d) calcining the product obtained in step c) to obtain the CaMgAl mixed oxide; a CaMgAl mixed oxide obtainable this way; and the use thereof.

The present invention provides lanthanide-supported transition metal catalysts synthesized using high-nitrogen energetic precursors; processes for the preparation of said catalysts and for coating inert ceramic monoliths with said catalysts; and uses thereof, e.g., in reforming of methane.

Provided is a shortened fibrous carbon nanohorn aggregate (CNB) obtained by shortening a CNB having a length of 1 m or more and a diameter in the short direction in the range of 30 to 100 nm, by oxidizing, stirring in an acid solution, subjecting to an ultrasonic treatment in a liquid, followed by cutting. The shortened CNB has an end surface on which no tip of the plurality of single-walled carbon nanohorns is disposed toward the longitudinal direction at least one end in the longitudinal direction, and has an excellent dispersibility by shortening the length to less than 1 m.

Provided is a shortened fibrous carbon nanohorn aggregate (CNB) obtained by shortening a CNB having a length of 1 m or more and a diameter in the short direction in the range of 30 to 100 nm, by oxidizing, stirring in an acid solution, subjecting to an ultrasonic treatment in a liquid, followed by cutting. The shortened CNB has an end surface on which no tip of the plurality of single-walled carbon nanohorns is disposed toward the longitudinal direction at least one end in the longitudinal direction, and has an excellent dispersibility by shortening the length to less than 1 m.