Ni Catalysts For Hydrogenation Research Articles

Origin of catalytic activity in sponge Ni catalysts for hydrogenation of carbonyl compounds

AbstractComputational results are presented from density function theory (DFT) that describe the reactivity of Al and early transition metal doped, sponge Ni catalysts. To develop an understanding of the catalytic activity of these materials, the direct reduction of acetaldehyde has been studied as a test system. Use of the scaling paradigm proposed by Norskov and co-worker shows the influence of dopant atoms upon the atomic adsorption energy of C and O and consequently adsorption energies of reaction intermediates. Construction of a simple kinetic model (parameterized from DFT) demonstrates that the presence of Al improves catalytic performance of carbonyl hydrogenation by increasing the reactivity towards O containing molecules, whilst at the same time decreasing the affinity towards C. Comparison is made to acetylene hydrogenation, where the activity is dependent on the C affinity of the catalysts. It is thus suggested that should one desire to selectively hydrogenate a carbonyl group in the presence o...

Influence of support on catalytic activity of Ni catalysts in p-nitrophenol hydrogenation to p-aminophenol

Abstract The catalytic activities of kieselguhr-, TiO2-, and Al2O3-supported Ni catalysts in hydrogenation of p-nitrophenol to p-aminophenol were investigated. The supported Ni catalysts were characterized by N2 adsorption/desorption, X-ray diffraction, temperature-programmed reduction, and temperature-programmed desorption of ammonia techniques. The catalytic activities of the supported Ni catalysts were in an order of Ni/kieselguhr ≫ Ni/TiO2 > Ni/Al2O3. The acidities of the supported Ni catalysts were in an order of Ni/Al2O3 ≫ Ni/TiO2 > Ni/kieselguhr. The acidity of the supported Ni catalyst significantly affected the catalytic activity.