Compositions, articles, and methods related to a three-way-catalyst composition comprising a perovskite-type compound of formula (I): La.sub.zB.sub.1-qB.sub.qO.sub.3 or formula (II): [BO.sub.x].sub.y:[La.sub.zBO.sub.3].sub.1-y and a non-redox active component; wherein B or B is Fe, Mn, Co, Ni, Cu, Ti, or Zr; q is in a range from about 0 to about 0.5; x is from about 1 to about 2.5; y is from about 1 to about 30 wt %; z is about 0.6 to about 1.1; is in a range from about 0 to about 0.6.

Compositions of manganese accumulating plants.

Compositions of manganese accumulating plants.

The invention relates to nanoporous gold nanoparticle catalysts formed by exposure of nanoporous gold to ozone at elevated temperatures, as well as methods for production of esters and other compounds.

The invention relates to nanoporous gold nanoparticle catalysts formed by exposure of nanoporous gold to ozone at elevated temperatures, as well as methods for production of esters and other compounds.

A platinum core-shell catalyst that uses palladium (Pd) as a core metal, or a platinum catalyst containing platinum and a metal besides platinum is manufactured industrially on a mass scale. The platinum catalyst is supported on carbon and has excellent oxygen reduction activity. The platinum catalyst is made for a fuel cell by bringing about the presence of a chemical species imparting higher potential than the initial oxide formation potential of the platinum of the platinum catalyst, and by bringing about the presence of a chemical species imparting lower potential than the initial oxide formation potential of the platinum of the platinum catalyst. The manufacture is carried out in a dispersion solution of the platinum catalyst dispersed in an acidic solution containing protons.

A process for the preparation of a catalyst comprising palladium, a porous support with a specific surface area in the range 140 to 250 m.sup.2/g, said catalyst being prepared by a process comprising the following steps: a) preparing a colloidal solution of palladium oxide or palladium hydroxide in an aqueous phase; b) adding said solution obtained from step a) to said porous support at a flow rate in the range 1 to 20 litre(s)/hour; said porous support being contained in a rotary impregnation device functioning at a rotational speed in the range 10 to 20 rpm; c) optionally, submitting the impregnated porous support obtained from step b) to a maturation; d) drying the catalyst precursor obtained from step b) or c); e) calcining the catalyst precursor obtained from step d).

Methods are provided for activation of catalysts comprising low amounts of a hydrogenation metal, such as low amounts of a Group 8-10 noble metal. The amount of hydrogenation metal on the catalyst can correspond to 0.5 wt % or less (with respect to the weight of the catalyst), or 0.1 wt % or less, or 0.05 wt % or less. Prior to loading a catalyst into a reactor, the corresponding catalyst precursor can be first activated in a hydrogen-containing atmosphere containing 1.0 vppm of CO or less. The thus first-activated catalyst can be transferred to a reactor with optional exposure to oxygen during the transfer, where it can be further activated using a hydrogen-containing atmosphere containing 3.0 vppm of CO or higher, to yield a twice-activated catalyst with high performance. The catalyst can be advantageously a transalkylation catalyst or an isomerization catalyst useful for converting aromatic hydrocarbons.

The use, after heat treatment, of manganese accumulating plants for carrying out chemical reactions.

The use, after heat treatment, of manganese accumulating plants for carrying out chemical reactions.