The present invention is a method of producing silicon compound coated oxide particles in which at least a part of a surface of a metal oxide particle is coated with a silicon compound, wherein wettability and color characteristics are controlled by controlling a ratio of SiOH bonds contained in the silicon compound coated oxide particles. By the present invention, silicon compound coated oxide particles having controlled wettability such as hydrophilicity, water repellency or oil repellency, and controlled color characteristics of either reflectivity, molar absorption coefficient or transmittance can be provided.

The present invention is a method of producing silicon compound coated oxide particles in which at least a part of a surface of a metal oxide particle is coated with a silicon compound, wherein wettability and color characteristics are controlled by controlling a ratio of SiOH bonds contained in the silicon compound coated oxide particles. By the present invention, silicon compound coated oxide particles having controlled wettability such as hydrophilicity, water repellency or oil repellency, and controlled color characteristics of either reflectivity, molar absorption coefficient or transmittance can be provided.

A method for the precipitation of rare earth sulphate, the method including subjecting a crude rare earth sulphate solution to precipitation in the presence of a water soluble, volatile, organic compound to produce a rare earth sulphate precipitate and an acidic supernatant. The organic compound is preferably selected from the group consisting of methanol, ethanol, iso-propanol, tert-butanol, acetone or mixtures thereof, and is preferably methanol. Preferably, the organic compound is used in the precipitation at a weight ratio of between 0.25:1 to 1.5:1, and preferably 0.5:to 1.25:1, with the crude sulphate solution.

A method for the precipitation of rare earth sulphate, the method including subjecting a crude rare earth sulphate solution to precipitation in the presence of a water soluble, volatile, organic compound to produce a rare earth sulphate precipitate and an acidic supernatant. The organic compound is preferably selected from the group consisting of methanol, ethanol, iso-propanol, tert-butanol, acetone or mixtures thereof, and is preferably methanol. Preferably, the organic compound is used in the precipitation at a weight ratio of between 0.25:1 to 1.5:1, and preferably 0.5:to 1.25:1, with the crude sulphate solution.

A hydrogen permeation membrane is provided that can include a carbon-based material (C) and a ceramic material (BZCYT) mixed together. The carbon-based material can include graphene, graphite, carbon nanotubes, or a combination thereof. The ceramic material can have the formula BaZr.sub.1-x-y-zCe.sub.xY.sub.yT.sub.zO.sub.3-, where 0x0.5, 0y0.5, 0z0.5, (x+y+z)>0; 00.5, and T is Yb, Sc, Ti, Nb, Ta, Mo, Mn, Fe, Co, Ni, Cu, Zn, Ga, In, or a combination thereof. In addition, the BZYCT can be present in the C-BZCYT mixture in an amount ranging from about 40% by volume to about 80% by volume. Further, a method of forming such a membrane is also provided. A method is also provided for extracting hydrogen from a feed stream.

A composition based on cerium and niobium oxide in a proportion of niobium oxide of 2% to 20% is described. This composition can include zirconium oxide, optionally 50% of cerium oxide, 2% to 20% of niobium oxide, and at most 48% of zirconium oxide. Also described, is the use of the composition for treating exhaust gases.

The present invention relates to silicon-compound-coated fine metal particles, with which surfaces of fine metal particles, composed of at least one type of metal element or metalloid element, are at least partially coated with a silicon compound and a ratio of SiOH bonds contained in the silicon-compound-coated fine metal particles is controlled to be 0.1% or more and 70% or less. By the present invention, silicon-compound-coated fine metal particles that are controlled in dispersibility and other properties can be provided by controlling the ratio of SiOH bonds or the ratio of SiOH bonds/SiO bonds contained in the silicon-compound-coated fine metal particles. By controlling the ratio of SiOH bonds or the ratio of SiOH bonds/SiO bonds, a composition that is more appropriate for diversifying applications and targeted properties of silicon-compound-coated fine metal particles than was conventionally possible can be designed easily.

The present invention relates to silicon-compound-coated fine metal particles, with which surfaces of fine metal particles, composed of at least one type of metal element or metalloid element, are at least partially coated with a silicon compound and a ratio of SiOH bonds contained in the silicon-compound-coated fine metal particles is controlled to be 0.1% or more and 70% or less. By the present invention, silicon-compound-coated fine metal particles that are controlled in dispersibility and other properties can be provided by controlling the ratio of SiOH bonds or the ratio of SiOH bonds/SiO bonds contained in the silicon-compound-coated fine metal particles. By controlling the ratio of SiOH bonds or the ratio of SiOH bonds/SiO bonds, a composition that is more appropriate for diversifying applications and targeted properties of silicon-compound-coated fine metal particles than was conventionally possible can be designed easily.

A highly stable gas sensor capable of detecting carbon dioxide is provided. A carbon dioxide gas sensor includes an insulating substrate and a gas sensing layer formed on one major surface of the insulating substrate via electrodes, in which the gas sensing layer comprises one or more rare earth oxides represented by Ln.sub.2O.sub.3, Ln being at least one rare earth metal element selected from Sc, Y, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Pr, Yb and Lu, and a method for producing the gas sensor are provided.

This disclosure generally relates to an oxide composition basically composed of cerium and zirconium that has exceptional and stable porosity, surface area and lattice oxygen mobility. The oxide composition can contain one or more other rare earth oxides other than cerium oxide. For example, some compositions can contain one or more of lanthanum oxide, yttrium oxide and neodymium oxide. The oxide composition can be useful as a catalyst, catalyst support, sensor applications and combinations thereof.