Effect of electron transfer in Pd on nitrogen-doped carbon nanotube catalysts in the Heck reaction

Abstract

In this study, the electron transfer effects of different nitrogen functional groups on palladium on nitrogen-doped carbon nanotube (Pd/N-CNT) catalysts for the Heck reaction were systematically investigated. Pd/N-CNTs were synthesized using a practical and scalable method via chemical vapor deposition and wet impregnation to precisely control the percentage of the different N species. Structural elucidation and catalytic performance testing revealed that the synthesis temperature significantly affected Pd/N-CNT structure. Moreover, the Pd-graphitic N complex was identified as the active-site in the Heck reaction, whereas the Pd-pyridinic N complex functioned as an inhibitor, while the Pd-pyrrolic N and Pd-NOx complexes were spectators.