Abstract: This invention relates to an aqueous dispersion of particles, the dispersion having a particle content of 10-70 wt %, and the particles comprising, on an oxide basis: (a) 10-98 wt % in total of ZrO2+HfO2, and (b) 2-90 wt % in total of Al2O3, CeO2, La2O3, Nd2O3, Pr6O11, Y2O3, or a transition metal oxide, wherein the dispersion has a Z-average particle size of 100-350 nm and the particles have a crystallite size of 1-9 nm. The invention also relates to a substrate coated with the aqueous dispersion of particles.

Abstract: This invention relates to azirconium hydroxideor zirconium oxide comprising, on an oxide basis, up to 30 wt % of a dopant comprising one or more of silicon, sulphate, phosphate, tungsten, niobium, aluminium, molybdenum, titanium or tin, and having acid sites, wherein the majority of the acid sites are Lewis acid sites. In addition, the invention relates to a catalyst, catalyst support or precursor, binder, functional binder, coating or sorbent comprising the zirconium hydroxide or zirconium oxide.

Abstract: A cerium-zirconium based mixed oxide composition have: (a) a Ce:Zr molar ratio of 1 or less, and (b) a cerium oxide content of 10-50% by weight. The composition has (i) a surface area of at least 18 m2/g, and a total pore volume as measured by N2 physisorption of at least 0.11 cm3/g, after ageing at 1100° C. in an air atmosphere for 6 hours, (ii) a surface area of at least 42 m2/g, and a total pore volume as measured by N2 physisorption of at least 0.31 cm3/g, after ageing at 1000° C. in an air atmosphere for 4 hours, and (iii) Dynamic Oxygen Storage Capacity (D-OSC) value as measured by H2-TIR of greater than 500 ?mol/g at 600° C. after aging at 800° C. in an air atmosphere for 2 hours. A process contacts the exhaust gas with the composition Another process is for preparing the composition.

Abstract: This invention relates to an aqueous dispersion of particles, the dispersion having a particle content of 10-70 wt %, and the particles comprising, on an oxide basis: (a) 10-98 wt % in total of ZrO2+HfO2, and (b) 2-90 wt % in total of AI2O3, CeO2, La2O3, Nd2O3, Pr6O11, Y2O3, or a transition metal oxide, wherein the dispersion has a Z-average particle size of 100-350 nm and the particles have a crystallite size of 1-9 nm. The invention also relates to a substrate coated with the aqueous dispersion of particles.

Abstract: A passive NOX adsorbent includes: palladium, platinum or a mixture thereof and a mixed or composite oxide including the following elements in percentage by weight, expressed in terms of oxide: 10-90% by weight zirconium and 0.1-50% by weight of least one of the following: a transition metal or a lanthanide series element other than Ce. Although the passive NOX adsorbent can include Ce in an amount ranging from 0.1 to 20% by weight expressed in terms of oxide, advantages are obtained particularly in the case of low-Ce or a substantially Ce-free passive NOx adsorbent.

Abstract: A passive NOX adsorbent includes: palladium, platinum or a mixture thereof and a mixed or composite oxide including the following elements in percentage by weight, expressed in terms of oxide: 10-90% by weight zirconium and 0.1-50% by weight of least one of the following: a transition metal or a lanthanide series element other than Ce. Although the passive NOX adsorbent can include Ce in an amount ranging from 0.1 to 20% by weight expressed in terms of oxide, advantages are obtained particularly in the case of low-Ce or a substantially Ce-free passive NOx adsorbent.

Abstract: A passive NOX adsorbent includes: palladium, platinum or a mixture thereof and a mixed or composite oxide including the following elements in percentage by weight, expressed in terms of oxide: 10-90% by weight zirconium and 0.1-50% by weight of least one of the following: a transition metal or a lanthanide series element other than Ce. Although the passive NOX adsorbent can include Ce in an amount ranging from 0.1 to 20% by weight expressed in terms of oxide, advantages are obtained particularly in the case of low-Ce or a substantially Ce-free passive NOx adsorbent.

Abstract: This invention relates to azirconium hydroxideor zirconium oxide comprising, on an oxide basis, up to 30 wt % of a dopant comprising one or more of silicon, sulphate, phosphate, tungsten, niobium, aluminium, molybdenum, titanium or tin, and having acid sites, wherein the majority of the acid sites are Lewis acid sites. In addition, the invention relates to a catalyst, catalyst support or precursor, binder, functional binder, coating or sorbent comprising the zirconium hydroxide or zirconium oxide.

Abstract: This invention relates to a cerium-zirconium based mixed oxide having: (a) a Ce:Zr molar ratio of 1 or less, and (b) a cerium oxide content of 10-50% by weight, wherein the composition has (i) a surface area of at least 18 m2/g, and a total pore volume as measured by N2 physisorption of at least 0.11 cm3/g, after ageing at 1100° C. in an air atmosphere for 6 hours, and (ii) a surface area of at least 42 m2/g, and a total pore volume as measured by N2 physisorption of at least 0.31 cm3/g, after ageing at 1000° C. in an air atmosphere for 4 hours. The invention also relates to a catalytic system comprising the cerium-zirconium based mixed oxide, as well as to a process 10 for treating an exhaust gas from a vehicle engine comprising contacting the exhaust gas with the cerium-zirconium based mixed oxide.

Abstract: The invention relates to a method for treating a gas containing nitrogen oxides (NOx), in which an NOx-reduction reaction is carried out using a nitrogen-containing reducing agent, which invention is characterized in that the catalyst used for the reduction reaction is a catalytic system containing a composition comprising zirconium, cerium and niobium in the following percentages by weight, expressed in terms of the weight of oxide: 10-50% of cerium, 5-20% of niobium and the remainder consisting of zirconium.

Abstract: A method is described for treating a gas including nitrogen oxides (NOx). The method can include conducting a reduction reaction of the nitrogen oxides with a nitrogen reducing agent. Further described, is a catalyst used for the reduction reaction which is a catalytic system including a composition based on cerium oxide and including niobium oxide in a proportion by a mass of from 2% to 20%.

Abstract: The invention relates to a method for treating a gas containing nitrogen oxides (NOx), in which an NOx-reduction reaction is carried out using a nitrogen-containing reducing agent, which invention is characterized in that the catalyst used for the reduction reaction is a catalytic system containing a composition comprising zirconium, niobium in the following percentages by weight, expressed in terms of the weight of oxide: 10-50% of cerium, 5-20% of niobium and the remainder consisting of zirconium.

Abstract: A method is described for treating a gas including nitrogen oxides (NOx). The method can include conducting a reduction reaction of the nitrogen oxides with a nitrogen reducing agent. Further described, is a catalyst used for the reduction reaction which is a catalytic system including a composition based on cerium oxide and including niobium oxide in a proportion by a mass of from 2% to 20%.