Nanoparticles in Catalysis

Catalysis plays a vital role in providing fuels, fine chemicals, Pharmaceuticals, and means for strengthening environmental safeguards. In comparison with many other fields of chemical and materials sciences, catalysis was perhaps one of the first fields to take advantage of nanotechnology. Supported noble metal catalysts with particle sizes down to a few hundred nanometers and zeolite catalysts with pore size of subnanometers, all developed in the 1950s–60s, are widely used in today’s chemical processes. The field of catalysis continuously reinvents itself and become highly interdisciplinary. Many of the recent advances, some of which are discussed in this chapter, are a result of such interdisciplinary developments involving nanotechnology. The nanotechnology-guided design and fabrication of catalysts, enhancement of catalytic activity or selectivity, and reduction in cost of catalysts will have enormous impacts to the chemical industry. The ability to harness the large surface area-tovolume ratios and the unique binding sites of nanoparticles (1–100 nm), especially in heterogeneous catalysis, constitutes a major driving force in fundamental research and practical applications of nanoparticle catalysts. Importantly, deliberate tailoring of nanoparticle size, shape and surface could lead to improved or new catalytic properties. This aspect was indeed inspired by the surprising discovery of high catalytic activity of nanosized gold towards oxidation or reduction of hydrocarbons.1–4 Gold is traditionally considered catalytically inactive as a practical catalyst, but this property is completely changed when the size dimension is reduced to a few nm.