A method of purifying air polluted by smoke and fumes, such as from wildfires and other hazard, may deploy a series of fluid filled vessels that act as filters to trap and/or neutralize components that would foul an aqueous suspension of gold nanoparticles that is effective in converting toxic carbon monoxide to carbon dioxide. Non-toxic fluids may be used. As the gold nanoparticles are effective in a basic solution, the solution may contain a visible pH indicator or an apparatus that deploys the method may continuously monitor the pH thereof.

A method of purifying air polluted by smoke and fumes, such as from wildfires and other hazard, may deploy a series of fluid filled vessels that act as filters to trap and/or neutralize components that would foul an aqueous suspension of gold nanoparticles that is effective in converting toxic carbon monoxide to carbon dioxide. Non-toxic fluids may be used. As the gold nanoparticles are effective in a basic solution, the solution may contain a visible pH indicator or an apparatus that deploys the method may continuously monitor the pH thereof.

A method for preparing methyl methacrylate from methacrolein and methanol. The process comprises contacting in a reactor a mixture comprising methacrolein, methanol and oxygen with a heterogeneous catalyst comprising a support and a noble metal, wherein said catalyst has an average diameter of at least 200 microns, liquid and gaseous reactants flow downward in the reactor and wherein the continuous phase in the reactor is a gas which has no more than 7.5 mol % oxygen at reactor inlets.

A method for preparing a heterogeneous catalyst. The method comprises steps of: (a) combining (i) a support, (ii) an aqueous solution of a noble metal compound and (iii) a C.sub.2-C.sub.18 thiol comprising at least one hydroxyl or carboxylic acid substituent; to form a wet particle and (b) removing water from the wet particle by drying followed by calcination to produce the catalyst.

A method for preparing a heterogeneous catalyst. The method comprises steps of: (a) combining (i) a support, (ii) an aqueous solution of a noble metal compound and (iii) a C.sub.2-C.sub.18 thiol comprising at least one hydroxyl or carboxylic acid substituent; to form a wet particle and (b) removing water from the wet particle by drying followed by calcination to produce the catalyst.

A novel process can be used for a heterogeneously catalysed oxidation reaction, in the presence of a pulverulent noble metal-containing catalyst, where (meth)acrolein, an alkyl alcohol, in particular methanol, and an oxygen-containing gas are converted to an alkyl (meth)acrylate, in particular methyl (meth)acrylate. A corresponding reactor suitable for performing the reaction is also useful. The process allows for an effective retention of the particulate catalyst and the continuous discharge of fines fractions of the catalyst powder which are present, particularly in a fresh catalyst batch as a consequence of its preparation. Such fines fractions may also be produced by abrasion during the reaction. The process allows for effective recycling, recovery, and utilization of these discharged catalyst fractions.

A process produces methyl methacrylate by direct oxidative esterification of methacrolein. Methyl methacrylate is used in large amounts for producing polymers and copolymers with other polymerizable compounds. An optimized workup of the reactor discharge from the oxidative esterification of methacrolein allows for co-discharged fine catalyst particles to be very efficiently separated and optionally removed or recycled. In addition, this process can reduce the formation of byproducts in extended continuous operation compared to known variant. A reactor system contains stirrer configurations which allow virtually abrasion-free operation and thus a catalyst on-stream time of several years.

This invention provides an anisotropic nanostructure represented by the formula:
Ru.sub.xM.sub.1-x,
wherein 0.6≤x≤0.999, and M represents at least one member selected from the group consisting of Ir, Rh, Pt, Pd, and Au, and wherein Ru and M form a solid solution at the atomic level, and the anisotropic nanostructure has an anisotropic hexagonal close-packed structure (hcp).

This invention provides an anisotropic nanostructure represented by the formula:
Ru.sub.xM.sub.1-x,
wherein 0.6≤x≤0.999, and M represents at least one member selected from the group consisting of Ir, Rh, Pt, Pd, and Au, and wherein Ru and M form a solid solution at the atomic level, and the anisotropic nanostructure has an anisotropic hexagonal close-packed structure (hcp).

A method of purifying air polluted by smoke and fumes, such as from wildfires and other hazard, may deploy a series of fluid filled vessels that act as filters to trap and/or neutralize components that would foul an aqueous suspension of gold nanoparticles that is effective in converting toxic carbon monoxide to carbon dioxide. Non-toxic fluids may be used. As the gold nanoparticles are effective in a basic solution, the solution may contain a visible pH indicator or an apparatus that deploys the method may continuously monitor the pH thereof.