Carbon nanotubes and catalysis: the many facets of a successful marriage

Abstract

Carbon nanotubes have emerged as unique carbon allotropes that bear very interesting prospects in catalysis. Their use is mostly related to that of supports for inorganic metal catalysts, including molecular catalysts, metal nanoparticles, metal oxides or even more complex hierarchical hybrids. However, several reports have shown that they can intriguingly act as metal-free catalysts, with performance often superior to that of other carbon materials, in particular when ad hoc organic functional groups are attached prior to catalytic screening. The range of catalytic reactions is quite wide, and it includes standard organic synthesis, electrocatalysis, photocatalysis as well as other important industrial processes. In the last few years, the energy sector has acquired a dominant role as one of the most sought-after fields of application, given its ever-increasing importance in society

Nucleation, Growth Mechanism, and Controlled Coating of ZnO ALD onto Vertically Aligned N-Doped CNTs

“…Indeed, CNTs have been already combined with a variety of inorganic compounds for applications in energy materials, catalysis, sensing, etc. [6,7].…”

“…The 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 2 conformal growth provided by ALD is a direct consequence of the process and ensures precise film thickness control and excellent step coverage, even on 3D structures with large aspect ratios [3,4]. In this context, ALD is quite suitable for the elaboration of complex nanostructured materials, including CNT-inorganic materials heterostructures [5][6][7] where the CNTs act as the template for depositing inorganic materials. In this way, the final functional material combines the properties of the carbon substrate such as good electrical conductivity, and mechanical and chemical resistance, with the ones of the coating material.…”

Noncovalently functionalized carbon nanotubes immobilized Fe–Bi bimetallic oxides as a heterogeneous nanocatalyst for reduction of nitroaromatics

“…However, the hydrophobicity and self-coalesce of the CNTs sometimes restrict their application. Consequently, the chemists have dedicated to functionalize the CNTs with different kinds of organic molecules, such as 3, 4-dihydroxybenzaldehyde [43], pyridine [44], imidazolium [45], quinine [46], so that the CNTs are kept in the dispersed status, the covalent and non-covalent functionalization strategies have been well developed. [47,48] However, grafting many hydrophilic groups with covalent bond on the CNTs may inevitably damage the CNT structures, while a non-covalent functionalization may preserve their good properties.…”

Hydrogenation of Phenol over Pt/CNTs: The Effects of Pt Loading and Reaction Solvents

“…Carbon nanotubes (CNTs) has been widely studied as a support of metal catalysts [11][12][13]. Surface modification of CNTs with oxygenated groups (e.g., carboxylic or hydroxyl) can be simplified by the pretreatment with HNO 3 , which has been reported as an effective method to optimize the performance of CNT-supported metal catalysts as well as purify and open the tips of CNTs [2].…”