CdSO4 and ZnSO4 as co-modifiers of RuLa/SBA-15 lead to improved catalysts for the partial hydrogenation of benzene to cyclohexene. Based on the experimental results and theoretical calculations, it is shown that CdSO4 acts as surface modification, suppressing more the adsorption of cyclohexene than that of benzene, while the function of ZnSO4 is mainly the stabilization of cyclohexene in the liquid phase, accelerating the desorption as well as hindering the re-adsorption of cyclohexene.

Cu/SiO2 catalysts prepared by the ammonia-evaporation (AE) method have been systematically characterized focusing on the effect of the AE temperature during catalyst preparation. It is found that the texture, composition, and structure of the calcined and reduced Cu/SiO2 catalysts were profoundly affected by the AE temperature. Based on characterizations and previous findings, the copper species on calcined Cu/SiO2 samples and reduced Cu/SiO2 catalysts were assigned. In gas-phase hydrogenation of dimethyl oxalate (DMO) to ethylene glycol (EG), the evolution of the catalytic activity with the Cu0 and Cu+surface areas suggested that Cu+ also participated in the hydrogenation process. The cooperative effect between Cu0 and Cu+ is proposed to be responsible for the highest hydrogenation activity of the Cu/SiO2 catalyst prepared at the AE temperature of 363 K, on which an EG yield of 98% was obtained under the optimized hydrogenation conditions.

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.

The textural and structural properties of a skeletal Ni catalyst prepared by alkali leaching of aluminum from the rapidly quenched Ni50Al50 alloy have been investigated by elemental analysis (ICP-AES), nitrogen physisorption, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and H2 thermal desorption techniques. As compared to Raney Ni, such a skeletal catalyst has a residual Ni2Al3 phase, lower surface area, higher average pore diameter and porosity, larger mean crystallite size, and unit-cell parameter. These differences are attributable to the metastable character of the pristine rapidly quenched alloy and their relationship with the catalytic behavior is discussed and correlated.

An environmentally benign SBA-15-supported amorphous nickel boride alloy catalyst, prepared by a novel reductant–impregnation method, exhibits superior activity, selectivity, and stability in the selective hydrogenation of 2-ethylanthraquinone (eAQ) to 2-ethylanthrahydroquinone (H2eAQ), which is the dominating process for the production of hydrogen peroxide in industrial scale. The unique characters of the amorphous alloy as well as the pore structure of the mesoporous SBA-15 molecular sieve are crucial for the excellent catalytic behavior of the title catalyst.