Metal-containing crystalline silicates
View Patent ↗Novel metal-containing silicates, in particular redox-active as well as crystalline silicates, a process for preparing metal-containing crystalline silicates, as well as use thereof as high-temperature oxidation catalyst or diesel oxidation catalyst. Further, a catalytic composition and a shaped catalyst body which contains the metal-containing crystalline silicates.
1. A process for preparing metal-containing crystalline silicates, wherein a metal is introduced into a gallo-silicate, gallo-titanium silicate, boro-silicate or boro-titanium silicate and the gallo-silicate, gallo-titanium silicate, boro-silicate or boro-titanium silicate is then calcined at temperatures above 600° C., wherein gallium or boron is removed from the crystal lattice, wherein the silicate has a zeolite structure, the topology is selected from the group consisting of AEL, BEA, CHA, EUU, FAU, FER, KFI, LTA, LTL, MAZ, MOR, MEL, MTW, LEV, OFF, TON and MFI and the metal is a noble metal or transition metal, wherein the metal is introduced into the gallo-, gallo-titanium-, boro- or boro-titanium silicate via an aqueous ion exchange, aqueous impregnation, incipient wetness method or solid-state exchange.
2. The process according to claim 1 , wherein the metal is introduced into the gallo-silicate, gallo-titanium silicate, boro-silicate or boro-titanium silicate in a quantity of from 0.1 to 15 wt.-%.
3. The process according to claim 1 , wherein the metal is selected from the group consisting of Pt, Pd, Au, Ag, Rh, Re, Ir, Mn, Fe and/or Cu.
4. The process according to claim 1 , wherein reduction with hydrogen takes place after the calcining.
5. The process according to claim 1 , wherein the metal is present in the silicate substantially in oxidation state (0).
6. The process according to claim 5 , wherein the silicate is free of Brønsted acid centers.
7. The process according to claim 6 , wherein the silicate comprises the metal in the range of from 0.1 to 15 wt.-%.