Catalysis of Organic..

230 Hydrogenation of Pynitrile%Selectivity from Pynitrile Hydrogenation100%99%98%97%96%1.71.996.41.02.296.81.31.996.80.10.299.7B 113 W (Ni) B 2112 Z (Co) Ni/SiO2 B 113 W (Ni)treated withFormaldehyde0.10.899.1B 2112 Z (Co)treated withFormaldehyde0.1Other productsSecondary aminePrimary amine1.898.1Ni/SiO2 treatedwithFormaldehydeFigure 2. Pynitrile hydrogenation over fresh and treated activated Ni (B 113 W),activated Co (B 2112 Z) and Ni/SiO 2 catalysts in the presence of NH 3 .%Selectivity from Pynitrile Hydrogenation100%99%98%97%96%1.799.71.9 98.80.196.4B 113 W (Ni)0.10.2Other productsSecondary aminePrimary amineB 113 W (Ni) treatedwith Formaldehyde0.11.1B 113 W (Ni) treatedwith Carbonmonoxide0.81.697.6B 113 W (Ni) treatedwith Acetone2.697.3B 113 W (Ni) treatedwith AcetaldehydeFigure 3. Pynitrile hydrogenation in NH 3 over B 113W after different modifications.In any case, the treatment of the catalyst results in a more selective (regardingthe formation of primary amine) hydrogenation of nitriles. This effect could beexplained on a molecular basis by electronic (work function) and/or steric effects bystrongly adsorbed species that function to partition the wide-open active surface ofNi and Co catalysts into smaller active sites composed of a controlled number of