Weakening the strong Fe-La interaction in A-site-deficient perovskite via Ni substitution to promote the thermocatalytic synthesis of carbon nanotubes from plastics.

The variation of metal-support interaction (MSI) plays a key role in the synthesis of carbon nanotubes (CNTs) based on chemical vapor deposition process. This work concentrates on weakening the interaction of Fe-La in an A-site-deficient perovskite (LaFeO) via Ni partial substitution. After reductive treatment, the catalysts were employed for thermocatalytic synthesis of CNTs from plastics. Following the structural, morphological and chemical changes, the catalytic activities of the reductive LaNiFeO (H-LNF, x = 0, 0.15, 0.5, 0.85) were correlated with the degree of MSI. Compared with H-LF sample, the H-LNF sample exhibited the highest catalytic activity, which was attributable to the highest surface coverage of metals as well as the synergistic effect of Fe and Ni species. The yield of CNTs produced from low density polyethylene was 1.44 g/g over the H-LNF sample, which was much higher than that over H-LF sample (0.38 g/g).