Screening of catalyst supports for efficient synthesis of carbon nanotubes: Utilization of natural cellulose fibers

This paper explores the feasibility of directly using natural cellulose fibers (CF) with uniform microstructure as catalyst supports to prepare carbon nanotubes (CNTs). Six different Ni-based catalysts are prepared using CF, lignin, biochar, activated carbon, Al 2 O 3 , and ZSM-5 as supports and used for CNTs growth. The reaction conditions including the growth temperature (600–800 ℃) and the metal loading (1–9 wt%) are studied for promoting the synthesis of high-quality CNTs. When the metal loading and the growth temperature are fixed at 5 wt% and 750 ℃, the highest degree of graphitization (I D /I G =0.74) and carbon yield (2080 mg/g cat ) are achieved on Ni/CF due to the optimal interaction between the metal and the support. The CNTs deposited on Ni/CF catalysts during methane decomposition mainly follow a tip growth mechanism. The catalytic performance of Ni-based catalysts on CF is superior to that of Fe- and Co-based catalysts, which is beneficial for CNTs graphitization.