Effects of functionalization and catalyst treatments on selective behavior of multi-walled carbon nanotube-supported palladium catalysts in hydrogenation of acetylene

Two nanocatalysts of palladium over multi-walled carbon nanotubes (MWCNT) were synthesized and their catalytic properties evaluated in selective hydrogenation of acetylene. Different procedures were applied to synthesize catalysts which resulted in two distinct average particle sizes of palladium (Pd) over the MWCNT. The resulting catalysts displayed dissimilar NH3-TPD behaviors as well as different selectivity performances at lower temperatures. While enhancement of the hydrogen transfer mechanism occurred upon the temperature increase, similar behaviors for the aforementioned materials were obtained. Furthermore, it was revealed that the catalytic performance at higher temperatures did not depend upon the Pd particle size or heterogeneous energetic sites formed during functionalizing of the MWCNT material.