The present disclosure provides for compositions, methods of making compositions, and methods of using the composition. In an aspect, the composition can be a reactive material that can be used to split a gas such as water or carbon dioxide.

The present disclosure provides for compositions, methods of making compositions, and methods of using the composition. In an aspect, the composition can be a reactive material that can be used to split a gas such as water or carbon dioxide.

Disclosed here is a method for making a monolithic rare earth oxide (REO) aerogel, comprising: preparing a reaction mixture comprising at least one rare earth metal nitrate, at least one epoxide, at least one base catalyst, and at least one organic solvent; curing the mixture to produce a wet gel; drying the wet gel to produce a dry gel; and thermally annealing the dry gel to produce the monolithic REO aerogel. Also disclosed is an REO aerogel comprising a network of REO nanostructures, wherein the REO aerogel is a monolith having at least one lateral dimension of at least 1 cm, wherein the REO aerogel has a density of about 40-500 mg/cm.sup.3 and/or a BET surface area of at least about 20 m.sup.2/g, and wherein the REO aerogel is substantially free of oxychloride.

Disclosed are a composite oxide which is capable of maintaining a large volume of pores even used in a high temperature environment, and which has excellent heat resistance and catalytic activity, as well as a method for producing the composite oxide and a catalyst for exhaust gas purification employing the composite oxide. The composite oxide contains cerium and at least one element selected from aluminum, silicon, or rare earth metals other than cerium and including yttrium, at a mass ratio of 85:15 to 99:1 in terms oxides, and has a property of exhibiting a not less than 0.30 cm.sup.3/g, preferably not less than 0.40 cm.sup.3/g volume of pores with a diameter of not larger than 200 nm, after calcination at 900° C. for 5 hours, and is suitable for a co-catalyst in a catalyst for vehicle exhaust gas purification.

Doped cerium oxide particles may comprise about 90 weight percent (wt. %) to about 99.9 wt. % cerium oxide (CeO.sub.2) and up to about 10 wt. % dopant. Exemplary doped cerium oxide particles may have a BET specific surface area of more than 150 m.sup.2/g after calcination at 500° C. for 8 hours. Exemplary doped cerium oxide particles may have an oxygen storage capacity (OSC) of more than 900 μmol.Math.O.sub.2/g after calcination at 500° C. for 8 hours.

High surface area, high entropy oxides comprising multiple metal cations in a single-phase fluorite lattice material enables intrinsic catalytic activity without platinum group metals, tunable oxygen storage capacity, and thermal stability. These properties can be obtained through a facile sol-gel synthesis to provide a low-temperature route for production of phase-pure multi-cationic oxides. The resulting materials achieved significantly higher surface area and catalytic performance, taking advantage of all the properties endowed by the various cations in the composition.

High surface area, high entropy oxides comprising multiple metal cations in a single-phase fluorite lattice material enables intrinsic catalytic activity without platinum group metals, tunable oxygen storage capacity, and thermal stability. These properties can be obtained through a facile sol-gel synthesis to provide a low-temperature route for production of phase-pure multi-cationic oxides. The resulting materials achieved significantly higher surface area and catalytic performance, taking advantage of all the properties endowed by the various cations in the composition.

Lanthanide oxides and mixed lanthanide oxides can be produced using furnace or microwave assisted solid-state synthesis. The use of Ln-tri(methylsilyl)amide-based precursors yields spherical nanoparticles. The formation of spherical shaped nanoparticles is likely due to the preferential single-step decomposition of the Ln-TMS as well as the low activation energy to overcome decomposition. Reaction temperature, initial metal ion ratio, and reaction dwell time can be used to control the final nanoparticle size. The method enables solvent-free, high-yield synthesis of morphology-controlled lanthanide oxides.

Lanthanide oxides and mixed lanthanide oxides can be produced using furnace or microwave assisted solid-state synthesis. The use of Ln-tri(methylsilyl)amide-based precursors yields spherical nanoparticles. The formation of spherical shaped nanoparticles is likely due to the preferential single-step decomposition of the Ln-TMS as well as the low activation energy to overcome decomposition. Reaction temperature, initial metal ion ratio, and reaction dwell time can be used to control the final nanoparticle size. The method enables solvent-free, high-yield synthesis of morphology-controlled lanthanide oxides.

The invention relates to a method of separating and extracting rare-earths from rare-earth polishing powder waste and regenerating rare-earth polishing powder, which is characterized by: firstly, process the waste powder with first acid leaching, alkali roasting, and second acid leaching to separate and extract rare-earths from rare-earth polishing powder waste to obtain the leaching solution of rare-earth chloride; secondly, precipitate from the leaching solution with ammonia to remove impurities and hydrochloric acid solution to obtain the purified solution of rare-earth chloride; thirdly, co-precipitate from the solution acquired in the second step with hydrofluoric acid, ammonium bicarbonate, and dispersant to obtain the lanthanum cerium fluoro-carbonate; and finally, after drying, two-stage high-temperature calcination, and ball milling, the regenerated rare-earth polishing powder with decent polishing performance can be obtained. The total leaching efficiency of rare-earths in the rare-earth polishing powder waste of the present invention reaches more than 95%, and the total recovery efficiency of rare-earths reaches more than 93%, which realizes the efficient separation, extraction, and regeneration of rare-earths in the rare-earth polishing powder waste.