This work introduces a novel sandwich-like structured nanocatalyst, which shows a large specifi c surface area, good dispersity and enhanced synergistic eff ects between CeO 2 and noble metals. This synthetic strategy is an eff ective method for the preparation of highly effi cient sandwich-like mesoporous catalysts.We report the creation of highly efficient sandwich-like structured nanocatalysts consisting of magnetic Fe 3 O 4 cores, porous SiO 2 and CeO 2 shells and coated with noble metal nanoparticles (NMNPs). The nanocatalysts possess uniform sizes, variable shell compositions and thicknesses, adjustable noble metal nanoparticle coatings, tunable morphologies and good structural stability, and can be used as unique catalysts with extremely high catalytic activity and stability for the 4-nitrophenol reduction reaction due to their structural features with multiple interactions and strong synergistic effects between the noble metal nanoparticles and the cerium oxide shells. The designed double shelled Fe 3 O 4 @SiO 2 @CeO 2 /M nanocatalysts can be used as novel catalyst systems with highly efficient catalytic performance for various catalytic reactions depending on their shell components and noble nanoparticle coating. The synthetic strategy provides a new methodology to design high-performance and recyclable nanocatalysts.

We reviewed recent advances in catalysts for PROX with emphasis on synergistic effects that contribute to enhanced catalytic performance.

Methyl formate is widely employed as one of the important organic intermediates in C1 chemistry and as an environmentally benign chemical in the emerging area of “green chemistry”. We here study the catalytic effectiveness of CuO/TiO2-nanotube nanocomposites for the direct synthesis of methyl formate via methanol photo-oxidation in this paper. The CuO/TiO2-nanotube nanocomposites with 7% CuO weight loading give a promising photocatalytic performance (over 93.3% methanol conversion and 89.4% methyl formate selectivity) at 25 °C under 365 nm UV irradiation. The turnover frequency and the apparent quantum efficiency reach up to 22.9 molmethanol gcat –1 h–1 and 57.6% over 7% CuO/TiO2-nanotube, respectively, which is mainly because of the effective minimization of the recombination of photogenerated electrons and holes by the surface ultrasmall-sized CuO particles. Furthermore, these CuO/TiO2-nanotube nanocomposites exhibit excellent durability and robust nature during the catalytic processes of the methanol photo-oxidation to methyl formate. The experimental results demonstrate the promise of the robust CuO/TiO2 nanocomposites for efficient and green production of methyl formate, which may offer guidelines for the design of efficient catalysts for selective alcohol conversion to other valuable chemicals.

No abstract

A new directed self-assembly strategy is developed to achieve 3D Pt/Pd nanocrystal superlattices with enhanced electrocatalytic performance for methanol oxidation reaction due to the enriched metallic Pt active sites by appropriate Pd alloying and surface nitrogen doping.

Significant current interest exists in the catalytic growth of carbon ͑C͒ nanotubes on clusters of transition metal catalysts. Here we focus on the elemental energetics for the atomistic rate processes involved in the initial stages of the growth by studying a C atom on a nickel ͑Ni͒ magic cluster (Ni 38 ), which preserves fcc geometry, and three low-index extended Ni surfaces. Our methods are based on density-functional theory. The binding energies of a C atom on the extended Ni surfaces and the corresponding facets on the Ni cluster have been obtained and compared. In spite of the large difference in the curvature, the preference order of the adsorption sites for both the cluster and the extended surfaces is unchanged, which shows that among the stable ͑100͒, ͑111͒ hcp, and ͑111͒ fcc sites the ͑100͒ has the lowest energy. The diffusion barriers for a C atom on the three low-index surfaces, namely ͑100͒, ͑110͒, and ͑111͒, have also been obtained, with the highest mobility on the Ni͑111͒ surface.

No abstract

No abstract