C01G5/00

Silver impregnation method for producing ethylene oxide catalyst with enhanced catalytic ability
10604497 · 2020-03-31 · ·

A method for producing a catalyst effective in the oxidative conversion of ethylene to ethylene oxide, the method comprising: (i) impregnating a porous refractory carrier with a sub-catalytic level of silver ion in a range of 0.1 wt % to 1 wt % of silver by weight of the carrier and silver, and at least partially reducing said silver ion to elemental silver to produce a low-silver catalyst precursor having isolated silver atoms or silver nanoparticles on surfaces of said refractory carrier; and (ii) further impregnating the low-silver catalyst precursor with a catalytic amount of silver ion of at least 10 wt % total amount of silver and at least one promoting species by weight of the carrier and silver, and subjecting the further impregnated carrier to an elevated temperature of at least 200 C. to completely reduce silver ion to elemental silver in the carrier. The low-silver catalyst precursor produced in step (i) is also described in detail. Methods for using the catalyst produced in step (ii) for the oxidative conversion of ethylene to ethylene oxide are also described.

RECOVERY OF GOLD AND/OR SILVER

The recovery of gold and/or silver from gold and/or silver containing material is generally described. The gold and/or silver can be recovered selectively, in some cases, such that gold and/or silver are at least partially separated from non-silver and/or non-gold material. Gold and/or silver may be recovered from material using mixtures of acids, in some instances. In some cases, the mixture can comprise nitric acid and at least one supplemental acid, such as sulfuric acid or phosphoric acid. The amount of nitric acid within the mixture can be, in some instances, relatively small compared to the amount of sulfuric acid or phosphoric acid within the mixture. In some cases, the recovery of gold and/or silver using the acid mixtures can be enhanced by transporting an electric current between an electrode and the gold and/or silver of the material. In some cases, acid mixtures can be used to recover silver from particular types of materials, such as material comprising silver metal and cadmium oxide and/or material comprising silver metal and tungsten metal.

RECOVERY OF GOLD AND/OR SILVER

The recovery of gold and/or silver from gold and/or silver containing material is generally described. The gold and/or silver can be recovered selectively, in some cases, such that gold and/or silver are at least partially separated from non-silver and/or non-gold material. Gold and/or silver may be recovered from material using mixtures of acids, in some instances. In some cases, the mixture can comprise nitric acid and at least one supplemental acid, such as sulfuric acid or phosphoric acid. The amount of nitric acid within the mixture can be, in some instances, relatively small compared to the amount of sulfuric acid or phosphoric acid within the mixture. In some cases, the recovery of gold and/or silver using the acid mixtures can be enhanced by transporting an electric current between an electrode and the gold and/or silver of the material. In some cases, acid mixtures can be used to recover silver from particular types of materials, such as material comprising silver metal and cadmium oxide and/or material comprising silver metal and tungsten metal.

Eco-friendly control of red palm weevil using green synthesized silver nanoparticles of chlorophyll derivatives

Silver nanoparticles made by a green synthesis method using silver nitrate and a chlorophyll derivative, such as a chlorophyllin are provided. The thus produced silver nanoparticles can have a crystalline structure and an average particle size ranging from about 10 nm to about 40 nm. The disclosed silver nanoparticles may be useful in treating, preventing, and/or reducing insect infestation of a variety of plants, particularly date palms.

Eco-friendly control of red palm weevil using green synthesized silver nanoparticles of chlorophyll derivatives

Silver nanoparticles made by a green synthesis method using silver nitrate and a chlorophyll derivative, such as a chlorophyllin are provided. The thus produced silver nanoparticles can have a crystalline structure and an average particle size ranging from about 10 nm to about 40 nm. The disclosed silver nanoparticles may be useful in treating, preventing, and/or reducing insect infestation of a variety of plants, particularly date palms.

Materials for near field transducers and near field transducers containing same

A device including a near field transducer, the near field transducer including gold (Au) and at least one other secondary atom, the at least one other secondary atom selected from: boron (B), bismuth (Bi), indium (In), sulfur (S), silicon (Si), tin (Sn), hafnium (Hf), niobium (Nb), manganese (Mn), antimony (Sb), tellurium (Te), carbon (C), nitrogen (N), and oxygen (O), and combinations thereof; erbium (Er), holmium (Ho), lutetium (Lu), praseodymium (Pr), scandium (Sc), uranium (U), zinc (Zn), and combinations thereof; and barium (Ba), chlorine (Cl), cesium (Cs), dysprosium (Dy), europium (Eu), fluorine (F), gadolinium (Gd), germanium (Ge), hydrogen (H), iodine (I), osmium (Os), phosphorus (P), rubidium (Rb), rhenium (Re), selenium (Se), samarium (Sm), terbium (Tb), thallium (Th), and combinations thereof.

Materials for near field transducers and near field transducers containing same

A device including a near field transducer, the near field transducer including gold (Au) and at least one other secondary atom, the at least one other secondary atom selected from: boron (B), bismuth (Bi), indium (In), sulfur (S), silicon (Si), tin (Sn), hafnium (Hf), niobium (Nb), manganese (Mn), antimony (Sb), tellurium (Te), carbon (C), nitrogen (N), and oxygen (O), and combinations thereof; erbium (Er), holmium (Ho), lutetium (Lu), praseodymium (Pr), scandium (Sc), uranium (U), zinc (Zn), and combinations thereof; and barium (Ba), chlorine (Cl), cesium (Cs), dysprosium (Dy), europium (Eu), fluorine (F), gadolinium (Gd), germanium (Ge), hydrogen (H), iodine (I), osmium (Os), phosphorus (P), rubidium (Rb), rhenium (Re), selenium (Se), samarium (Sm), terbium (Tb), thallium (Th), and combinations thereof.

Ozone-Mediated Synthesis of Nanostructures

A method of producing ceria nanocrystals is provided. The method includes providing a gas that includes ozone to a solution that includes a cerium salt, and obtaining ceria nanocrystals from the solution after the gas is provided to the first solution. A method of producing nanoparticles is provided. The method includes providing a gas that includes ozone to a solution that includes a metal salt that includes at least one of a transition metal or a lanthanide, and producing at least one of metal oxide nanoparticles, metal oxynitrate nanoparticles, or metal oxyhydroxide nanoparticles from the solution after the gas is provided to the solution.

Ozone-Mediated Synthesis of Nanostructures

A method of producing ceria nanocrystals is provided. The method includes providing a gas that includes ozone to a solution that includes a cerium salt, and obtaining ceria nanocrystals from the solution after the gas is provided to the first solution. A method of producing nanoparticles is provided. The method includes providing a gas that includes ozone to a solution that includes a metal salt that includes at least one of a transition metal or a lanthanide, and producing at least one of metal oxide nanoparticles, metal oxynitrate nanoparticles, or metal oxyhydroxide nanoparticles from the solution after the gas is provided to the solution.

Thermoelectric material, and preparation method therefor and application thereof

The present application discloses a thermoelectric material, which contains CsAg.sub.5Te.sub.3 crystal material. At 700K, the thermoelectric material has an optimum dimensionless figure-of-merit ZT as high as 1.6 and a high stability, and the thermoelectric material can be recycled. The present application also discloses a method for preparing the CsAg.sub.5Te.sub.3 crystal material. The CsAg.sub.5Te.sub.3 crystal material is one-step synthesized by a high-temperature solid-state method, using a raw material containing Cs, Ag and Te, so that the high-purity product is obtained while the synthesis time is greatly shortened.