Layered composite carrier for producing shell shaped catalyst

Abstract

The invention relates to a layered composite carrier used for preparing thin-shell catalysts, and solves the technical problems that the prior layered composite carrier has small specific surface area, and the relevant thin-shell noble metal catalyst has low dispersity, poor utilization rate and low selectivity. In order to solve the problems, the technical scheme is as follows: the layered composite carrier used for preparing thin-shell catalysts, comprises an inert carrier inner core and a porous coating as outer layer conjugated on the inner core. The carrier inner core is at least one substance selected from alpha-Al2O3, theta-Al2O3, metals, SiC, cordierite, zirconium oxide, titanium oxide, quartz, mullite and Al-rich andalusite. The porous coating is at least one substance selected from gamma-Al2O3, delta-Al2O3, eta-Al2O3, theta-Al2O3, silicon oxide / aluminum oxide, zeolite, non-zeolite molecular sieves, titanium oxide and zirconium oxide. The layered composite carrier is applied to the industrial production of thin-shell catalysts.

Description

technical field

[0001] The invention relates to a layered composite support for preparing thin-shell catalysts. Background technique

[0002] At present, a considerable part of catalysts used in chemical and oil refining processes are supported catalysts using noble metals as active components. Because precious metals are expensive, their content in catalysts tends to be low. Studies have found that the non-uniform distribution of active components in the carrier can reduce the amount of precious metals and improve the utilization of precious metals; at the same time, in many reactions, catalysts with non-uniform distribution also show better activity, selectivity and life. The most important one is the eggshell catalyst, that is, the surface thin shell type with active components concentrated on the surface of the carrier. When the rate<<intrinsic reaction rate, if the reaction rate is very fast, the reactant molecules will react as soon as they diffuse into the ch...

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