The invention provides a composite material formed from an inorganic mesoporous, or mesoporous-like, material that is dispersed throughout a polymeric matrix formed by a crosslinked polymer that has acidic- or basic-residues and which may also optionally have further acidic- or basic-residues grafted onto the inorganic mesoporous material. The resulting composite material may be used to remove acidic or basic impurities from a gas in need thereof and can be easily regenerated.

Embodiments of the present disclosure are directed towards methods for preparing mixed-metal oxide particles by heating adamantane-intercalated layered double-hydroxide (LDH) particles at a reaction temperature of from 400° C. to 800° C. to form mixed-metal oxide particles. The adamantane-intercalated LDH particles have a general formula [M.sub.1-xAl.sub.x(OH).sub.2](A).sub.x.mH.sub.2O, where x is from 0.14 to 0.33, m is from 0.33 to 0.50, M is chosen from Mg, Ca, Co, Ni, Cu, or Zn, and A is adamantane carboxylate, and an aspect ratio greater than 100. The aspect ratio is defined by the width of an adamantane-intercalated LDH particle divided by the thickness of the adamantane-intercalated LDH particle. The mixed-metal oxide particles comprise a mixed-metal oxide phase containing M, Al or Fe, and carbon.

Provided are mixed metal oxy-hydroxides that serve as reactive media to bind, sequester, or alter one or more toxic chemicals such as sulfur dioxide (SO.sub.2), hydrogen cyanide (HCN), and others. A reactive media includes: a porous metal oxy-hydroxide including at least one first transition metal that is optionally one or more of copper, zinc, or iron; a second transition metal linked to the first transition metal by a bond that includes an oxygen, the second transition metal selected optionally being one or more of magnesium, calcium, cobalt, titanium, zirconium, aluminum, and silicon; and the metal oxy-hydroxide terminated by at least one hydroxyl group. The resulting media provides for excellent porosity and reactivity for removal of toxic chemicals from the environment or a sample.

Disclosed are processes for removing H.sub.2S from gas streams containing H.sub.2S, the processes comprise contacting gas streams with a mixed metal oxy-hydroxide media comprising two or more metals selected from the group consisting of magnesium, chromium, manganese, iron, cobalt, zinc and copper. Also disclosed are processes for removing H.sub.2S from gas streams containing H.sub.2S, the processes comprise contacting the gas streams with a mixed metal oxy-hydroxide media comprising one or more metals selected from the group listed above plus one or more metals selected from the group consisting of aluminum, silicon, titanium and zirconium.

A mixed salt composition adapted for use as a sorbent for carbon dioxide removal from a gaseous stream is provided, the composition being in solid form and including magnesium oxide, an alkali metal carbonate, and an alkali metal nitrate, wherein the composition has a molar excess of magnesium characterized by a Mg:X atomic ratio of at least about 3:1, wherein X is the alkali metal. A process for preparing the mixed salt is also provided, the process including mixing a magnesium salt with a solution comprising alkali metal ions, carbonate ions, and nitrate ions to form a slurry or colloid including a solid mixed salt including magnesium carbonate; separating the solid mixed salt from the slurry or colloid to form a wet cake; drying the wet cake to form a dry cake including the solid mixed salt; and calcining the dry cake to form a mixed salt sorbent.

A manganese oxide contains M1, optionally M2, Mn and O. M1 is selected from the group consisting of In, Sc, Y, Dy, Ho, Er, Tm, Yb and Lu. M2 is different from M1, and M2 is selected from the group consisting of Bi, In, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. These ceramic materials are hexagonal in structure, and provide superior materials for gas separation and oxygen storage.

A filtration device including a fluid-impermeable housing having a gas inlet and outlet, and containing within the housing first filter media particles of an extended surface area substrate and containing at least one metal impregnant, and second filter media particles of an extended surface area zirconium hydroxide substrate and containing zinc (hydr)oxide. The first or second filter media particles also contain an amine-functional material. The device may be used in atmospheres containing various harmful gases, and may provide particularly useful improvements in breakthrough times for nitrogen dioxide, hydrogen sulfide, ammonia and formaldehyde compared to a device containing only the first filter media particles or only the second filter media particles.

A high-efficient particulate air filter assembly including a high efficient particulate air filter for filtering the intake air as it enters an air purifying system is provided. The air filter assembly can further include a housing configured for use in an air purification system; a first prefilter positioned in the housing upstream from the particulate air filter; and an electrostatically charged substrate positioned in the housing downstream from the particulate air filter. The air filter assembly can further include a second prefilter having a paper layer; a carbon layer; a zeolite layer; a mesh layer; and a foam layer.

Simultaneous method for the production of carbon black and carbon nanostructures, where the gases produced from the carbon black manufacturing process are utilized as feedstock in an integrated process for the production of carbon nanostructures.

Disclosed is an adsorbent containing a metal oxide for adsorption of hydrogen sulfide in biogas, and a biogas purification system using the same.