Embodiments relate to a cerium-containing nano-coating composition, the composition including an amorphous matrix including one or more of cerium oxide, cerium hydroxide, and cerium phosphate; and crystalline regions including one or more of crystalline cerium oxide, crystalline cerium hydroxide, and crystalline cerium phosphate. The diameter of each crystalline region is less than about 50 nanometers.

The invention relates to a catalyst carrier for exhaust gas purification catalyst which contains a metal phosphate containing Zr, and it provides a new catalyst carrier which exhibits excellent NOx purification performance in a high temperature region. The invention proposes a carrier for exhaust gas purification catalyst containing a metal phosphate which has a NASICON type structure and contains Zr.

A porous zirconia-based composite oxide satisfying all of the following (1) to (3) in a range of 2 nm or more and 200 nm or less in a pore distribution based on a BJH method, and having a pore volume of 0.01 cm.sup.3/g or more and 0.25 cm.sup.3/g or less in a range of more than 100 nm and 1000 nm or less in a pore distribution based on a mercury intrusion method, (1) a dV/d log D peak is in a range of 2 nm or more and 100 nm or less; (2) a maximum value of the dV/d log D peak is 1.5 or more and 5.0 or less; (3) a pore volume in a range of 2 nm or more and 100 nm or less is 0.30 cm.sup.3/g or more and 1.50 cm.sup.3/g or less.

An object of the present invention is to provide an exhaust gas purification catalyst having improved exhaust gas (e.g., NOx) purifying performance at low to medium temperature. In order to achieve the object, the present invention provides an exhaust gas purification catalyst including: a substrate; and a catalyst layer formed on the substrate, wherein the catalyst layer contains rhodium element, phosphorus element and a rare earth element other than cerium element, wherein a ratio of a mass of the phosphorus element contained in the catalyst layer to the mass of the rhodium element contained in the catalyst layer is from 1 to 10, and wherein a ratio of a mass of the rare earth element other than cerium element in terms of an oxide thereof contained in the catalyst layer to the mass of the rhodium element contained in the catalyst layer is from 1 to 5.

The present invention relates to a composition for use in a catalyst system in emission control systems comprising a transition alumina based material and rare earth phosphates and to a method for making same.

Disclosed are a catalyst for synergistic removal of nitrogen oxides (NO.sub.x) and CO as well as a preparation method and use thereof. The preparation method comprises: performing vibratory ball milling, washing, drying and calcining on aluminum isopropoxide and/or titanium isopropoxide, chlorides of five or more different metal elements and P123 and/or polyethylene glycol (PEG), stirring the obtained high-entropy oxide inner core and a gel of H.sub.3PO.sub.4 and Ce(NO.sub.3).sub.3, and then performing vibratory ball milling, washing, drying and calcining to obtain an high-entropy oxide loaded with CePO.sub.4 seeds; and preparing, by using ammonia water, a clear solution containing pyrophosphate and Ce(NO.sub.3).sub.3 in equal stoichiometric ratios, then adding the high-entropy oxide loaded with the CePO.sub.4 seeds and urea and/or tetrapropylammonium hydroxide (TPAH) to form a slurry, and, after hydrothermal reaction, washing, drying and calcining a solid to obtain the catalyst.