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 nanoparticles, the nanoparticles comprising, on an oxide basis: (a) 85-100 wt % ZrO2+HfO2, (b) 0-15 wt % Y2O3, and (c) 0-2 wt % Al2O3, wherein the dispersion has a polydispersity index of 0.10-0.17. The invention also relates to a method of forming a ceramic article comprising the steps of: (a) pouring the aqueous dispersion into a mould, (b) drying the aqueous dispersion in the mould to form a green body, and (c) sintering the green body to form the ceramic article.

Abstract: A magnesium alloy suitable for use as a corrodible downhole article. The alloy has a corrosion rate of at least 50 mg/cm2/day in 15% KCl at 93° C. and a 0.2% proof strength of at least 50 MPa when tested using standard tensile test method ASTM B557-10.

Abstract: A corrodible downhole article includes a magnesium alloy. The magnesium alloy includes: 1-9 wt % Zn; 1-2 wt % Cu; 0.5-1.0 wt % Mn; and 0.1-5 wt % of a corrosion promoting element (e.g., Ni). The alloy can have a 0.2% proof strength of at least 150 MPa when tested using standard tensile test method ASTM B557-10.

Abstract: A magnesium alloy is suitable for use as a corrodible downhole article, wherein the alloy includes: (a) 2-7 wt % Gd, (b) 0-2 wt % Y, (c) 0-5.0 wt % Nd, and (d) at least 80 wt % Mg, and has an elongation as measured by ASTM B557M-10 of at least 22%.

Abstract: A magnesium alloy is suitable for use as a corrodible downhole article, wherein the alloy includes: (a) 11-15 wt % Y, (b) 0.5-5 wt % in total of rare earth metals other than Y, (c) 0-1 wt % Zr, (d) 0.1-5 wt % Ni, and (e) at least 70 wt % Mg. It has been surprisingly found by the inventors that by increasing the Y content of the alloy to the range specified above, increased age hardening response and hence increased 0.2% proof stress can be achieved.

Abstract: Magnesium alloys which possess good processability and/or ductility while retaining good resistance to corrosion and/or degradation comprising Y: 0-10% by weight, Nd: 0-5% by weight, wherein the total of Y+Nd is at least 0.05% by weight, one or more heavy rare earths selected from Ho, Lu, Tm and Tb in a total amount of above 0.5% and no more than 5.5% by weight, Gd: 0-3.0% by weight, and Sm: 0-0.2% by weight. The alloy optionally includes one or more of: Dy: 0-8% by weight; Zr: 0-1.2% by weight; Al: 0-7.5% by weight; Zn and/or Mn: 0-2% by weight in total; Sc: 0-15% by weight; In: 0-15% by weight; Ca: 0-3% by weight; Er up to 5.5% by weight, provided that the total of Er, Ho, Lu, Tm and Tb is no more than 5.5% by weight; and one or more rare earths and heavy rare earths other than Y, Nd, Ho, Lu, Tm, Tb, Dy, Gd and Er in a total amount of up to 0.5% by weight; the balance being magnesium and incidental impurities up to a total of 0.3% by weight.

Abstract: A composition based on cerium, zirconium and tungsten is described. The composition has a content expressed as an oxide, of which cerium is from 5% to 30% of the composition, tungsten is from 2% to 17% of the composition, and the remainder of the composition is zirconium. After aging at 750° C. under an air atmosphere including 10% water, it has a two-phase crystallographic structure having a tetragonal zirconia phase and a monoclinic zirconia phase, with no presence of a crystalline phase including tungsten. The composition can be used as a catalyst, especially in an SCR process.

Abstract: Magnesium alloys containing: Y: 2.0-6.0% by weight Nd: 0-4.0% by weight Gd: 0-5.5% by weight Dy: 0-5.5% by weight Er: 0-5.5% by weight Zr: 0.05-1.0% by weight Zn+Mn: <0.11% by weight, optionally other rare earths and heavy rare earths, the balance being magnesium and incidental impurities and the total content of Gd, Dy and Er is in the range of 0.3-12% by weight, wherein either the alloy contains low amounts of Yb and Sm and exhibits a corrosion rate as measured according to ASTM B 117 of less than 30 Mpy, and/or the area percentage of any precipitated particles arising when the alloy is processed having an average particle size greater than 1 [mu]m and less than 15 [mu]m is less than 3%.

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: 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 zirconium-based mixed oxide or zirconium-based mixed hydroxide which is capable of (a) at least 90% v/v conversion of naphthalene at atmospheric pressure at a temperature in the range 600-700° C. using a residence time of about 0.3 seconds, and/or (b) providing an initial heat of adsorption of ammonia of greater than 150 kJ/mol when measured by ammonia flowing gas microcalorimetry. Also, a method for purifying gas produced from the gasification of carbonaceous materials, comprising the step of bringing the gas into contact with such mixed oxides or mixed hydroxides.

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: Magnesium alloys which possess good processability and/or ductility whilst retaining good resistance to corrosion and/or degradation comprising Y: 0-10% by weight, Nd: 0-5% by weight, wherein the total of Y+Nd is at least 0.05% by weight, one or more heavy rare earths selected from Ho, Lu, Tm and Tb in a total amount of above 0.5% and no more than 5.5% by weight, Gd: 0-3.0% by weight, and Sm: 0-0.2% by weight. The alloy optionally includes one or more of: Dy: 0-8% by weight; Zr: 0-1.2% by weight; Al: 0-7.5% by weight; Zn and/or Mn: 0-2% by weight in total; Sc: 0-15% by weight; In: 0-15% by weight; Ca: 0-3% by weight; Er up to 5.5% by weight, provided that the total of Er, Ho, Lu, Tm and Tb is no more than 5.5% by weight; and one or more rare earths and heavy rare earths other than Y, Nd, Ho, Lu, Tm, Tb, Dy, Gd and Er in a total amount of up to 0.5% by weight; the balance being magnesium and incidental impurities up to a total of 0.3% by weight.

Abstract: This invention relates to the utilization of regenerable water tolerant solid materials for the abatements of CO2 emissions from internal combustion engine exhaust streams through repetitive sorption/desorption cycles. The system, which is designed to be used in a gasoline, lean gasoline, diesel passenger car, diesel truck, stationary engine with 50 Hz or 60 Hz electrical frequency, or a SOFC, will contain a solid sorbent which contains zirconium and will be able to reduce on board the average carbon emissions by up to 10 wt %. The preferred materials have been selected from the class of hydrotalcite type compounds and/or earth and alkaline earth zirconates.

Abstract: A composition based on cerium, zirconium and tungsten is described. The composition has a content expressed as an oxide, of which cerium is from 5% to 30% of the composition, tungsten is from 2% to 17% of the composition, and the remainder of the composition is zirconium. After aging at 750° C. under an air atmosphere including 10% water, it has a two-phase crystallographic structure having a tetragonal zirconia phase and a monoclinic zirconia phase, with no presence of a crystalline phase including tungsten. The composition can be used as a catalyst, especially in an SCR process.

Abstract: The present invention relates to oxygen storage components for catalytic converters for automobile exhaust systems, particularly for those with petrol-driven engines. In accordance with the present invention there is provided a ceria containing mixed oxide suitable as an oxygen storage material having a ceria content in the range 10 to 80% by weight and at least one metal oxide in an amount of less than 0.5% by weight, wherein the metal is selected from the first row transition elements and the group IVB elements of the periodic table. The inventions also provides an oxygen storage material for catalytic converters for automobile exhaust systems comprising an oxide of the present invention.

Abstract: Compositions useful for treating the exhaust gases of diesel engines contain zirconium oxide, silicon oxide and at least one oxide of at least one element M selected from among titanium, aluminum, tungsten, molybdenum, cerium, iron, tin, zinc, and manganese, in the following mass proportions of these different elements: silicon oxide: 5%-30%; M-element oxide: 1%-20%; the balance being zirconium oxide; such compositions also have an acidity, as measured by the methylbutynol test, of at least 90% and are prepared by placing a zirconium compound, a silicon compound, at least one M-element compound and a basic compound in a liquid medium, thereby generating a precipitate, maturing the precipitate in a liquid medium and separating and calcining the precipitate.