TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred System: The system have a surface to volume ratio of 250-1500. The system further comprises at least one additional nanoparticle; a monolayer of surfactant bound to at least a portion of the surface of the copper oxide nanoparticle; and surfactant bound to at least a portion of the surface of the copper oxide nanoparticle. Preferred Components: The copper oxide nanoparticle has the structure Cu2O-CuO; and is Cu(I)/Cu(II) oxide nanoparticle. The core comprises crystalline copper-cuprous oxide (Cu-Cu2O). The cupric oxide (CuO) has a thickness of up to 1 nm. The copper oxide nanoparticle has a diameter of 2-40 (preferably 4-25) nm. The copper oxide nanoparticles are highly monodisperse, such that the root mean square deviation from the diameter is less than 10 (preferably less than 5)%. The spacer is silica gel, alumina and/or zeolite (preferably silica gel).    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The surfactant is of formula R1(C=X)Y' or its salt (preferably oleic acid, lauric acid, octanoic acid, stearic acid, 1-octadecanol, elaidic acid, 2-acetyl pyridine, para-anisaldehyde, butyrolactone, 1-formyl piperidine, ethylene carbonate, propylene carbonate, gamma-buytrolactone, catechol and/or benzylamine oleylamine, especially oleic acid).R1=10-30C alkyl, 10-30C alkenyl or 10-30C cycloalkyl (all optionally substituted);X=O, S or NOH;andY'=-O-(10-30C) alkyl or -O-(10-30C) alkenyl (both optionally substituted) or OH.Preferred Method: The method (M1) involves oxidizing carbon monoxide (CO) to carbon dioxide (CO2); reducing nitrogen dioxide (NO2), nitric oxide (NO) or sulfur dioxide SO2; oxidizing hydrocarbon; and coupling at least two aryl halides (Ullmann coupling), where each of the aryl halide is optionally the same. The starting material is carbon monoxide, nitric acid, nitrogen dioxide, nitric oxide, sulfur dioxide, hydrocarbon, or at least two aryl halides. The chemical reaction occurs at less than 400 (preferably less than 300, especially less than 250)degreesC. The nanoparticle is prepared by a method involving contacting copper acetate, oleic acid and trioctylamine; and heating (preferably at 200-300, especially 220-250degreesC) in the presence of inert gas (preferably nitrogen (N2) and/or argon (Ar)) for at least 30 minutes, to provide thermally decomposed copper acetate; cooling to thermally decomposed the copper acetate (preferably at room temperature) to provide cooled particles; contacting the cooled particles with a solvent (preferably polar organic solvent and/or polar protic organic solvent, especially ethanol (neat)), and separating (preferably by centrifuging) to provide precipitated copper oxide nanoparticles; and redispersing the precipitated copper oxide nanoparticles in the presence of second solvent (preferably non-polar aprotic organic solvent, especially hexane). EXAMPLE - Cuprous oxide nanoparticles were synthesized according to procedure described in Yin, M.; Wu, C. K.; Lou, Y.; Burda, C; Koberstein, J. T.; Zhu, Y.; O'Brien, S. JAm Chem Soc 2005, 127, 9506-11, where Cu(I) acetate (4 mmol), technical grade (90%) oleic acid (4 ml), and trioctylamine (15 ml) were placed in flask and heated to 180degreesC to remove any low boiling point impurities and then allowed to thermally decompose under argon at 270degreesC for 1 hour. The particles were then cooled to room temperature, precipitated by adding pure ethanol (40 ml), centrifuging, and redispersed in hexanes (30 ml). In the hexanes, the deep red Cu nanoparticles oxidized to dark green cuprous oxide nanoparticles with a thin layer (0.5-1 nm) of CuO over the next few hours. Transmission electron micrographs (TEM) showed the nanoparticles were 4-25 nm in diameter. X-ray diffraction (XRD) revealed the nanoparticles to be crystalline cuprous oxide. The nanoparticles as catalyst were then tested under conditions typically used in systems. The results showed that the catalyst worked at a higher conversion for a longer period of time when compared to a catalyst of 10 mg 10 nm Cu2O nanoparticles mixed with 7 mg of 4 nm CeO2 nanoparticles on 75 mg of silica gel. The catalyst used nanoparticles over 4-12 nm range and showed size dependence. Additionally, the catalyst was found to have a lifetime of 220 hours. In contrast, the longest lifetimes reported of 20 minutes.