Cu2O nanocrystals exposing crystal planes

However, Cu2O nanocrystals exposing (111) crystal planes were catalytically superior in CO oxidation than cubes exposing (100) planes and rhombic dodecahedrons exposing (110) planes. This was due to unsaturated CuI sites existing in (111) crystal planes and thus was most active in chemisorbing CO and catalyzing CO oxidation. Loading of copper (4–25 wt%) onto nanostructured mesoporous ZrO2 significantly improved the catalytic activity and selectivity in methanol decomposition to CO and H2 by (i) the creation of additional surface acidic sites that contributed to the generation of methoxy intermediates, (ii) stabilization of Cu2 +/Cu+ and Cu+/Cu0 redox pairs where the electron transfer was facilitated by zirconia support, and (iii) assisting the recombination and release of hydrogen during the transformation of the intermediates produced on zirconia surface. At about 4% copper loading, the formation of CuO monolayer on mesoporous ZrO2 occurred [226]. Dispersed copper oxide nanocatalysts supported on activated carbon were prepared for catalytic oxidation of toluene in the air. Catalytic activity increased with both increasing calcination temperature and metal loading. However, well-dispersed nanocatalysts showed higher efficiency toward the oxidation of toluene [227]. Nanoscaled particles of Cu1 − xZnx(Al, Ga)2O4 spinel were prepared by a microwave-assisted hydrothermal method [228]. Cu incorporation into the Zn(Al, Ga)2O4 matrix nanostructure was lower for Ga-based spinels leading to higher particle size phases of < 20 nm in comparison with Al-based spinels (< 10 nm). Despite their high SSA (~ 300 m2 g− 1), reduced materials exhibited an exposed Cu0 metallic surface area of 8 m2 g− 1 in the case of Cu1 − xZnxAl2O4 and a 3.2-m2 g− 1 in the case of Cu1 − xZnxGa2O4. Their lower catalytic performance in CO2 hydrogenation and methanol steam reforming compared with conventionally prepared Cu/ZnO/Al2O3 catalysts was attributed to the structural incorporation of Cu and Zn ions rather than their ionic ones state in the conventional catalysts. This lower performance is attributed to the lack of synergetic interaction between Cu2 + and Zn2 + moieties in the above spinel structures. The results demonstrated the crucial role of the microstructural arrangement of the components in a Cusingle bondZnsingle bondAlsingle bondO composite catalyst on the nanoscale. They showed that ZnO's synergetic role for Cu-based catalysts was inhibited through Zn incorporation into a crystalline spinel host lattice. If you are looking for high quality, high purity, and cost-effective Copper oxide, or if you require the latest price, please email contact mis-asia.