Palladium Promoted Production of Higher Amines from a Lower Amine Feedstock

The catalytic (Pd/Al2O3 and Pd/C; mean Pd size 2.5–3.0 nm from (S)TEM analysis) synthesis of di-butylamine (DBA) and tri-butylamine (TBA) from mono-butylamine (MBA) and DBA, respectively, in continuous gas phase operation is demonstrated. Exclusive production of DBA (from MBA) has been established over both catalysts where 453 ≤ T ≤ 523 K (∆Ea = 79 kJ mol−1). Greater activity for Pd/C is associated with higher levels of surface acidity (from NH3 chemisorption/TPD) and spillover hydrogen (from H2 TPD). Reaction of DBA over both catalysts when configured in series delivered full selectivity to TBA. Our results establish a novel clean alternative route for the continuous production of higher (secondary and tertiary) amines.