An efficient green method for the synthesis of noble metal/transition metal oxide nanocomposite comprising reducing noble metal salt and a templating metal oxide is disclosed. The method is a one-step method comprises mixing coffee seed husk extract, a noble metal precursor, and a transition metal precursor; and filtering and drying the nanocomposite. The nanocomposite prepared by the method of the invention displays all the characteristics and biocidal activity of a composite prepared by traditional methods.

The present disclosure provides a method for preparing a degradative sol, the method comprising providing an aqueous dispersion of titanium dioxide nanoparticles, providing gold and/or silver precursor compound(s) to the dispersion, illuminating the dispersion with ultraviolet light to photodeposit gold and/or silver nanoparticles onto the titanium dioxide nanoparticles to obtain photocatalytic plasmonic nanoparticles having a plasmonic resonance frequency in visible spectrum of electromagnetic radiation, and providing the photocatalytic plasmonic nanoparticles as a degradative sol. The present disclosure also provides a degradative sol, a degradative surface, a method for providing a degradative surface and a method for degrading organic substances.

The present disclosure provides a method for preparing a degradative sol, the method comprising providing an aqueous dispersion of titanium dioxide nanoparticles, providing gold and/or silver precursor compound(s) to the dispersion, illuminating the dispersion with ultraviolet light to photodeposit gold and/or silver nanoparticles onto the titanium dioxide nanoparticles to obtain photocatalytic plasmonic nanoparticles having a plasmonic resonance frequency in visible spectrum of electromagnetic radiation, and providing the photocatalytic plasmonic nanoparticles as a degradative sol. The present disclosure also provides a degradative sol, a degradative surface, a method for providing a degradative surface and a method for degrading organic substances.

A process for producing a silver-based epoxidation catalyst, comprising i) impregnating a particulate porous refractory support with a first aqueous silver impregnation solution comprising silver ions and an aminic complexing agent selected from amines, alkanolamines and amino acids; ii) converting at least part of the silver ions impregnated on the refractory support to metallic silver by heating while directing a stream of a first gas over the impregnated refractory support to obtain an intermediate catalyst, wherein the first gas comprises at least 5 vol.-% oxygen; iii) impregnating the intermediate catalyst with a second aqueous silver impregnation solution comprising silver ions, an aminic complexing agent selected from amines, alkanolamines and amino acids, and one or more transition metal promoters, in particular rhenium; and iv) converting at least part of the silver ions impregnated on the intermediate catalyst to metallic silver by heating while directing a stream of a second gas over the impregnated intermediate catalyst to obtain the epoxidation catalyst, wherein the second gas comprises at most 2.0 vol.-% oxygen, wherein the impregnated refractory support and the impregnated intermediate catalyst are each heated to a temperature of 200 to 800° C. The process of the invention surprisingly allows for obtaining a catalyst with high selectivity in a cost-efficient manner. The invention also relates to a silver-based epoxidation catalyst obtainable by such a process, and to a process for producing an alkylene oxide by gas-phase oxidation of an alkylene, comprising reacting an alkylene and oxygen in the presence of a silver-based epoxidation catalyst obtainable by the above process.

The present disclosure relates to methods for selectively hydrogenating acetylene, to methods for starting up a selective hydrogenation reactor, and to hydrogenation catalysts useful in such methods. In one aspect, the disclosure provides a method for selectively hydrogenating acetylene, the method comprising contacting a catalyst composition with a process gas. The catalyst composition comprises a porous support, palladium, and one or more ionic liquids. The process gas includes ethylene, present in the process gas in an amount of at least 20 mol. %; and acetylene, present in the process gas in an amount of at least 1 ppm. At least 90% of the acetylene present in the process gas is hydrogenated, and the selective hydrogenation is conducted without thermal runaway. Notably, the process gas is contacted with the catalyst at a gas hourly space velocity (GHSV) based on total catalyst volume in one bed or multiple beds of at least 7,100 h.sup.−1.

The present disclosure relates to methods for selectively hydrogenating acetylene, to methods for starting up a selective hydrogenation reactor, and to hydrogenation catalysts useful in such methods. In one aspect, the disclosure provides a method for selectively hydrogenating acetylene, the method comprising contacting a catalyst composition with a process gas. The catalyst composition comprises a porous support, palladium, and one or more ionic liquids. The process gas includes ethylene, present in the process gas in an amount of at least 20 mol. %; and acetylene, present in the process gas in an amount of at least 1 ppm. At least 90% of the acetylene present in the process gas is hydrogenated, and the selective hydrogenation is conducted without thermal runaway. Notably, the process gas is contacted with the catalyst at a gas hourly space velocity (GHSV) based on total catalyst volume in one bed or multiple beds of at least 7,100 h.sup.−1.

In various embodiments, an air purifier capable of destroying and deactivating airborne contaminants such as SARS-CoV-2 is described. The air purifier comprises a photocatalytic system comprising at least one photoactivated semiconductor photocatalyst and a lamp configured to irradiate and excite the at least one photoactivated semiconductor photocatalyst to generate reductive and/or oxidative reactive species from oxygen and/or water on the photocatalyst surface. In various embodiments, the photocatalytic system comprises a stack of PCB cards, each card having a photocatalytic layer disposed thereon, or a 3-dimensionally ordered macroporous (3-DOM) structure comprising an open cell lattice.

A self-disinfecting photocatalyst sheet includes a substrate material and a photocatalyst layer with a primary photocatalyst and a secondary photocatalyst. The primary photocatalyst is a metal oxide photocatalyst, whereas the secondary photocatalyst is a metallic photocatalyst. The primary photocatalyst forms a covalent bond with the substrate material. The self-disinfecting photocatalyst sheet is photocatalytic active to different bands of wavelength. Another self-disinfecting photocatalyst sheet includes a substrate material, a prime material layer and a photocatalyst layer with a primary photocatalyst and a secondary photocatalyst. The prime material layer is between the substrate and the photocatalyst layer. The primary photocatalyst forms a covalent bond with the prime material.

A self-disinfecting photocatalyst sheet includes a substrate material and a photocatalyst layer with a primary photocatalyst and a secondary photocatalyst. The primary photocatalyst is a metal oxide photocatalyst, whereas the secondary photocatalyst is a metallic photocatalyst. The primary photocatalyst forms a covalent bond with the substrate material. The self-disinfecting photocatalyst sheet is photocatalytic active to different bands of wavelength. Another self-disinfecting photocatalyst sheet includes a substrate material, a prime material layer and a photocatalyst layer with a primary photocatalyst and a secondary photocatalyst. The prime material layer is between the substrate and the photocatalyst layer. The primary photocatalyst forms a covalent bond with the prime material.

A vehicle system includes a diesel oxidation catalyst. The vehicle system includes a hydrocarbon-selective catalytic reduction unit located downstream of the diesel oxidation catalyst. The hydrocarbon-selective catalytic reduction unit is configured to receive exhaust gas from the diesel oxidation catalyst. The vehicle system includes a turbocharger located downstream of the hydrocarbon-selective catalytic reduction unit. The turbocharger is configured to receive exhaust gas from the hydrocarbon-selective catalytic reduction unit.