Reactivity of Ni–Carbon Nanofibers/Mesocellular Silica Composite Catalyst for Phenylacetylene Hydrogenation

Abstract

In this research, a novel composite catalyst, Ni-carbon nanofibers (CNFs) supported on mesocellular silica (MS), has been successfully prepared with an attempt to improve the activity in liquid-phase phenylacetylene hydrogenation. Consequently, the MS support was prepared by modifying the pore size of SBA-15 mesoporous silica using a swelling agent, 1,3,5-trimethylbenzene (TMB). After that, nickel nanoparticles were loaded onto the MS support via an impregnation method, and CNFs were consecutively synthesized using nickel nanoparticles on the MS support as the catalyst in the catalytic chemical vapor deposition (CCVD) process. The obtained Ni–CNFs/MS catalyst with unique composite structure consisting of nickel active metals on the tips of CNFs was examined for its hydrophobicity and activity. It was found that the composite catalysts with CNFs synthesis times of 1 and 3 h (Ni–CNFs(1)/MS and Ni–CNFs(3)/MS) had a relative hydrophobicity of approximately 1.1 and 1.5 times higher than that without CNFs, respectively. Moreover, the turnover frequency (TOF) of Ni–CNFs/MS catalyst was also significantly increased with increasing the amount of Ni–CNFs composites on the MS support. Accordingly, Ni–CNFs(3)/MS catalyst exhibited the highest TOF (4.32 s–1); which was approximately 3.2 times higher than that of Ni/MS catalyst due to the hydrophobic surface property of CNFs and unique composite structure of Ni–CNFs/MS catalyst.