Nanocatalysts and their Applications
Researchers at the University of Houston have demonstrated the use of
nanoparticles as a photocatalyst to produce hydrogen and oxygen gas
from water using visible light. More work needs to be done, both to
increase the energy efficiency and the lifespan of the nanoparticles,
before this catalyst is commercially feasible.
Using gold nanoparticles embedded in a porous manganese oxide
as a room temperature catalyst to breakdown volatile organic compounds
nanocatalyst containing cobalt and platinum to remove nitrogen oxide from smokestacks
Reducing the amount of
platinum used in catalytic converters.
Researchers at Ulsan National Institute of Science and Technology
have demonstrated how to produce
edge-halogenated graphene nanoplatelets
that have good catalytic properties. The researchers prepared
the nanoplatelets by ball-milling graphene flakes in the presence of
chlorine, bromine or iodine. They believe these halogenated
nanoplatelets could be used as a replacement for expensive platinum
catalystic material in fuel cells.
Researchers at Cornell University have developed a
using platinum-cobalt nanoparticles that produces 12 times more
catalytic activity than pure platinum. In order to achieve this
performance the researchers annealed the nanoparticles so they formed a
crystalline lattice which reduced the spacing between platinum atoms on
the surface, increasing their reactivity.
Researchers at the University of Copenhagen
have demonstrated the ability to significantly reduce
the amount of platinum needed as a catalyst in fuel
cells. The researchers found that the spacing
between platinum nanoparticles affected the catalytic
behavior, and that by controlling the
packing density of the platinum nanoparticles they
could reduce the amount of platinum needed.
Researchers at Brown University are developing a catalyst that uses
no platinum. The catalyst is made from a sheet of
graphene coated with cobalt
nanoparticles. If this catalyst works out for production use with
fuel cells it should be much less expensive than platinum based
Researchers at Stony Brook University have demonstrated that gold
nanoparticles can be very effective at using solar energy to generate
hydrogen from water. The key is making the nanoparticles very small.
They found that
nanoparticles containing less than a dozen gold atoms are very
effective photocatalysts for the generation of hydrogen.
Researchers at the SLAC National Accelerator Laboratory have developed a way to use less platinum for the cathode in a fuel cell, which could significantly reduce the cost of fuel cells. They alloyed platinum with copper and then removed the copper from the surface of the film, which caused the platinum atoms to move closer to each other (reducing the lattice space). It turns out that
platinum with reduced lattice spacing is more a more effective catalyst for breaking up oxygen molecules into oxygen ion. The difference is that the reduced spacing changes the electronic structure of the platinum atoms so that the separated oxygen ions more easily released, and allowed to react with the hydrogen ions passing through the proton exchange membrane.
Another way to reduce the use of platinum for catalyst in fuel cell cathodes is being developed by researchers at Brown University. They deposited a one nanometer thick layer of platinum and iron on spherical nanoparticles of palladium. In laboratory scale testing they found that an
catalyst made with these nanoparticles generated 12 times more current
than a catalyst using pure platinum, and lasted ten times longer.
The researchers believe that the improvement is due to a more efficient
transfer of electrons than in standard catalysts.