摘要:
Methods for manufacturing carbon nanostructures include 1) forming intermediate carbon nanostructures by polymerizing a carbon precursor in the presence of templating nanoparticles, 2) carbonizing the intermediate carbon nanostructures to form an intermediate composite nanostructure, and 3) removing the templating nanoparticles from the intermediate composite nanostructure to form carbon nanorings. The carbon nanorings manufactured using the foregoing steps have one or more carbon layers forming a wall that defines a generally annular nanostructure having a hole. The length of the nanoring is less than or about equal to the outer diameter thereof. The carbon nanostructures are well-suited for use as a fuel cell catalyst support. The carbon nanostructures exhibit high surface area, high porosity, high graphitization, and facilitate mass transfer and electron transfer in fuel cell reactions. Carbon nanorings manufactured according to the present invention can be used as a substitute for more expensive and likely more fragile carbon nanotubes.
摘要:
Conductive polymers are purified using a solid scavenger. The solid scavengers include metal-scavenging functional groups linked to the surface of a particle support material. To improve the functionalization of the support material, the support materials are first treated with sulfuric acid or nitric acid before attaching the molecules containing the metal-scavenging functional groups. The solid scavengers used in the purification methods are more efficient at removing impurities in conductive polymers than existing scavengers.
摘要:
Organic ligands that contain at least one aryl group are immobilized on a solid support. The organic ligands are of the type used to form a catalyst complex suitable for carrying out a catalytic reaction, preferably an asymmetric reaction. To immobilize the organic ligands, a tethering group is bonded to the ligand using, for exarnple, a Friedel-Crafts acylation or alkylation reaction. The immobilization of the organic ligand can be carried out using a single reaction with the organic ligand.
摘要:
A catalyst manufacturing process includes heat treating an intermediate catalyst composition that includes catalyst nanoparticles having catalyst atoms in a non-zero oxidation state bonded to a dispersing/anchoring agent. The catalyst nanoparticles are formed using a dispersing agent having at least one functional group selected from the group of a hydroxyl, a carboxyl, a carbonyl, an amide, an amine, a thiol, a sulfonic acid, sulfonyl halide, an acyl halide, an organometallic complex, and combinations of these. The dispersing agent can be used to form single- or multicomponent supported nanocatalysts. The dispersing agent also acts as an anchoring agent to firmly bond the nanocatalyst to a support. Performing the heat treating process in an inert or oxidative environment to maintain the catalyst atoms in a non-zero oxidation helps maintains a stronger bonding interaction between the dispersing agent and the catalyst atoms. This, in turn, increases the dispersion and/or distribution of catalyst components throughout the supported catalyst.
摘要:
Methods for manufacturing carbon nanostructures include: 1) forming a plurality of catalytic templating particles using a plurality of dispersing agent molecules; 2) forming an intermediate carbon nanostructure by polymerizing a carbon precursor in the presence of the plurality of templating nanoparticles; 3) carbonizing the intermediate carbon nanostructure to form a composite nanostructure; and 4) removing the templating nanoparticles from the composite nanostructure to yield the carbon nanostructures. The carbon nanostructures are well-suited for use as a catalyst support. The carbon nanostructures exhibit high surface area, high porosity, and high graphitization. Carbon nanostructures according to the invention can be used as a substitute for more expensive and likely more fragile carbon nanotubes.
摘要:
A supported catalyst for hydrogenating nitro groups of halonitro compounds manufactured from a support, a solvent, and one or more types of organometallic complexes. The organometallic complexes have the formula: wherein, R1-R6 are independently an R, OR, OC(═O)R, halogen, or combination thereof, where R stands for an alkyl or aryl group; Y1-Y4 are independently an O, S, N, or P atom; and M is a metal atom. The supported catalysts show much higher selectivity and activity when used to hydrogenate nitro groups on halonitro aromatic compounds than catalyst currently being used for such hydrogenation.
摘要:
The fuel cells include electrode membrane assemblies having a nanoparticle catalyst supported on carbon nanorings. The carbon nanorings are formed from one or more carbon layers that form a wall that defines a generally annular nanostructure having a hole. The length of the nanoring is less than or about equal to the outer diameter thereof. The nanorings exhibit high surface area, high porosity, high graphitization, and/or facilitate mass transfer and electron transfer in fuel cell reactions.
摘要:
A catalyst manufacturing process includes heat treating an intermediate catalyst composition that includes catalyst nanoparticles having catalyst atoms in a non-zero oxidation state bonded to a dispersing/anchoring agent. The catalyst nanoparticles are formed using a dispersing agent having at least one functional group selected from the group of a hydroxyl, a carboxyl, a carbonyl, an amide, an amine, a thiol, a sulfonic acid, sulfonyl halide, an acyl halide, an organometallic complex, and combinations of these. The dispersing agent can be used to form single- or multicomponent supported nanocatalysts. The dispersing agent also acts as an anchoring agent to firmly bond the nanocatalyst to a support. Performing the heat treating process in an inert or oxidative environment to maintain the catalyst atoms in a non-zero oxidation helps maintains a stronger bonding interaction between the dispersing agent and the catalyst atoms. This, in turn, increases the dispersion and/or distribution of catalyst components throughout the supported catalyst.
摘要:
Methods for manufacturing carbon nanostructures include 1) forming intermediate carbon nanostructures by polymerizing a carbon precursor in the presence of templating nanoparticles, 2) carbonizing the intermediate carbon nanostructures to form an intermediate composite nanostructure, and 3) removing the templating nanoparticles from the intermediate composite nanostructure to form carbon nanorings. The carbon nanorings manufactured using the foregoing steps have one or more carbon layers forming a wall that defines a generally annular nanostructure having a hole. The length of the nanoring is less than or about equal to the outer diameter thereof. The carbon nanostructures are well-suited for use as a fuel cell catalyst support. The carbon nanostructures exhibit high surface area, high porosity, high graphitization, and facilitate mass transfer and electron transfer in fuel cell reactions. Carbon nanorings manufactured according to the present invention can be used as a substitute for more expensive and likely more fragile carbon nanotubes.
摘要:
Methods for manufacturing carbon nanostructures include: 1) forming a plurality of catalytic templating particles using a plurality of dispersing agent molecules; 2) forming an intermediate carbon nanostructure by polymerizing a carbon precursor in the presence of the plurality of templating nanoparticles; 3) carbonizing the intermediate carbon nanostructure to form a composite nanostructure; and 4) removing the templating nanoparticles from the composite nanostructure to yield the carbon nanostructures. The carbon nanostructures are well-suited for use as a catalyst support. The carbon nanostructures exhibit high surface area, high porosity, and high graphitization. Carbon nanostructures according to the invention can be used as a substitute for more expensive and likely more fragile carbon nanotubes.