The present invention relates to a process for the preparation of a catalyst for selective catalytic reduction comprising (i) preparing a mixture comprising a metal-organic framework material comprising an ion of a metal or metalloid selected from groups 2-5, groups 7-9, and groups 11-14 of the Periodic Table of the Elements, and at least one at least monodentate organic compound, a zeolitic material containing a metal as a non-framework element, optionally a solvent system, and optionally a pasting agent, (ii) calcining of the mixture obtained in (i); and further relates to a catalyst per se comprising a composite material containing an amorphous mesoporous metal and/or metalloid oxide and a zeolitic material, wherein the zeolitic material contains a metal as non-framework element, as well as to the use of said catalyst.

The invention provides an automotive catalyst composite that includes a catalytic material on a carrier, the catalytic material including a plurality of core-shell support particles including a core and a shell surrounding the core, wherein the core includes a plurality of particles having a primary particle size distribution d.sub.90 of up to about 5 ?m, wherein the core particles include particles of one or more molecular sieves and optionally particles of one or more refractory metal oxides; and wherein the shell comprises nanoparticles of one or more refractory metal oxides, wherein the nanoparticles have a primary particle size distribution d.sub.90 in the range of about 5 nm to about 1000 nm (1 ?m); and optionally, one or more platinum group metals (PGMs) on the core-shell support. The invention also provides an exhaust gas treatment system and related method of treating exhaust gas utilizing the catalyst composite.

A catalyst powder according to the present invention is a catalyst powder that includes: a core portion that contains ceria and zirconia; and a surface layer portion that is located on the core portion and contains ceria and zirconia. The ratio (M.sub.2/M.sub.1) is 0.30 or more and 0.95 or less, the ratio (M.sub.2/M.sub.1) being the ratio of a mole fraction M.sub.2 (mol %) of cerium in the surface layer portion measured using X-ray photoelectron spectroscopy to a mole fraction M.sub.1 (mol %) of cerium in the entire powder. It is preferable that the ratio (M.sub.4/2/M.sub.3/1) between M.sub.3/1 and M.sub.4/2 is 1.1 or more and 5.0 or less, wherein M.sub.3/1 (=M.sub.3/M.sub.1) represents the ratio between a mole fraction M.sub.3 (mol %) of zirconium in the entire powder and a mole fraction M.sub.1 (mol %) of cerium in the entirety of the powder, and M.sub.4/2 (=M.sub.4/M.sub.2) represents the ratio between a mole fraction M.sub.4 (mol %) of zirconium measured using X-ray photoelectron spectroscopy and a mole fraction M.sub.2 (mol %) of cerium measured using X-ray photoelectron spectroscopy.