Effect of microstructures of Pt catalysts supported on carbon nanotubes (CNTs) and activated carbon (AC) for nitrobenzene hydrogenation

Pt catalysts supported on carbon nanotubes (CNTs) and activated carbon (AC) were prepared. The structure of the catalysts was characterized using BET, TEM, XPS techniques. The catalytic performance for nitrobenzene hydrogenation was tested. The results show that the mesoporous textures of CNTs make the outer surfaces of CNTs accessible for Pt ion. So Pt particles on CNTs are much smaller, and the proper concentration of surface groups on CNTs makes Pt easy for reducibility. Pt particles on AC are larger due to the microporous texture, and reduction at higher temperature is necessary because of more functional groups on AC. The Pt/CNTs catalysts reduced at lower temperature, exhibit higher activity than the Pt/AC catalysts for nitrobenzene hydrogenation.