Binary CoB and ternary CoFeB amorphous alloy catalysts with different Fe contents were prepared by the chemical reduction method. In liquid-phase hydrogenation of crotonaldehyde, incorporation of Fe into the CoB catalyst reduced the overall activity while effectively improving the selectivity and yield to crotyl alcohol. On the optimum CoFeB-3 catalyst with a nominal Fe/(Co+Fe) molar ratio of 0.6, the initial selectivity amounted to 71%, and the yield of crotyl alcohol reached 63%. It is found that the selectivity enhancement was due to the lower decrement in the intrinsic formation rate of crotyl alcohol compared with that of butanal, not to the increment in the activation of the C=O bond. Based on the characterizations, including X-ray photoelectron spectroscopy and X-ray absorption spectroscopy, and previous findings, the enhanced selectivity from Fe modification was tentatively attributed to an ensemble size effect.

Liquid-phase hydrogenation of 2-ethylanthraquinone to 2-ethylanthrahydroquinone has been investigated over Raney Ni, nanosized amorphous Ni-B, and chromium-modified Ni-B catalysts. It has been found that the amorphous Ni-0B and chromium-modified Ni-B catalysts exhibited superior selectivity, whereas the chromium-modified Ni-B catalysts had better activity and selectivity than unmodified Ni-B catalyst. Based on the characterizations, the higher selectivity of the amorphous catalysts is ascribed to the dominant population of the strongly bound hydrogen, which is not reactive for the hydrogenation of the aromatic ring, along with the repulsive interaction between the aromatic ring and the electron-rich Ni due to electron donation from alloying B. The addition of chromium decreased the particle size of the amorphous catalysts, which is beneficial for the improvement of activity. Moreover, surface chromium oxide can function as a Lewis acid, which lowers the π? CO orbital of the reactant, favoring a carbonyl group-bonded configuration. The best selectivity was achieved over the Ni-Cr-B2 catalyst, where the hydrogenation of the aromatic ring was thoroughly blocked before the saturation of the carbonyl groups.

Zeolite analcime with a core-shell and hollow icositetrahedron architecture was prepared by a one-pot hydrothermal route in the presence of ethylamine and Raney Ni. Detailed investigations on samples at different preparation stages revealed that the growth of the complex single crystalline geometrical structure did not follow the classic crystal growth route, i.e., a crystal with a highly symmetric morphology (such as polyhedra) is normally developed by attachment of atoms or ions to a nucleus. A reversed crystal growth process through oriented aggregation of nanocrystallites and surface recrystallization was observed. The whole process can be described by the following four successive steps. (1) Primary analcime nanoplatelets undergo oriented aggregation to yield discus-shaped particles. (2) These disci further assemble into polycrystalline microspheres. (3) The relatively large platelets grow into nanorods by consuming the smaller ones, and meanwhile, the surface of the microspheres recrystallizes into a thin single crystalline icositetrahedral shell via Ostwald ripening. (4) Recrystallization continues from the surface to the core at the expense of the nanorods, and the thickness of the monocrystalline shell keeps on increasing until all the nanorods are consumed, leading to hollow single crystalline analcime icositetrahedra. The present work adds new useful information for the understanding of the principles of zeolite growth.

Liquid-phase hydrogenation of 2-ethylanthraquinone to 2-ethylanthrahydroquinone has been investigated over Raney Ni, nanosized amorphous Ni-B, and chromium-modified Ni-B catalysts. It has been found that the amorphous Ni-B and chromium-modified Ni-B catalystsexhibited superior selectivity, whereas the chromium-modified Ni-B catalysts had better activity and selectivity than unmodified Ni-B catalyst. Based on the characterizations, the higher selectivity of the amorphous catalysts is ascribed to the dominant population of the stronglybound hydrogen, which is not reactive for the hydrogenation of the aromatic ring, along with the repulsive interaction between the aromatic ring and the electron-rich Ni due to electron donation from alloying B. The addition of chromium decreased the particle size of the amorphous catalysts, which is eneficial for the improvement of activity. Moreover, surface chromium oxide can function as a Lewis acid, which lowers the 7r80 0rbital of the reactant. favoring a carbonyl group-bonded configuration. The best selectivity was achieved over the Ni-Cr-B2 catalyst, where the hydrogenation of the aromatic ring was thoroughly blocked before the saturation of the carbonyl groups.

A nanosized amorphous Ni-Cr-B catalyst prepared by the chemical reduction method exhibited superior thermal stability and selectivity in hydrogen peroxide synthesis via the anthraquinone route.