Catalysts play an extremely important role in modern industry; they help speed up chemical reactions by lowering the energy you need to get one started. This is a catalyst made up of a palladium nanoparticle (blue atoms) with a hydroxylated aluminum oxide "overcoat" (the aluminum atoms are pink, the oxygen atoms are red and the hydrogen atoms are white), with a carbon monoxide molecule (carbon atom is green, oxygen atom is red). Argonne scientists are using molecular simulations to study and improve nanoscale catalysts, which are used for getting energy from renewable sources. Nanoparticles are particles between 1 and 100 nanometers in size. In nanotechnology, a particle is defined as a small object that behaves as a whole unit with respect to its transport and properties. Particles are further classified according to diameter. Nanoparticle research is currently an area of intense scientific interest due to a wide variety of potential applications in biomedical, optical and electronic fields. Nanotechnology (nanotech) is the manipulation of matter on an atomic, molecular, and supramolecular scale.