Three different carbon nanoforms (CNFs), single-walled and multi-walled carbon nanotubes (SWCNTs, MWCNTs) and carbon nanohorns (CNHs), have been used as supports for the direct polymerization of variable amounts of a bis-vinylimidazolium salt. Transmission electron microscopy confirmed that all CNFs act as templates on the growth of the polymeric network, which perfectly covers the nanocarbons forming a cylindrical (SWCNTs, MWCNTs) or spherical (CNHs) coating. The stability of these hybrid materials was investigated in the conversion of CO₂ into cyclic carbonate under high temperature and CO₂ pressure. Compared with the homopolymerized monomer, nanotube-based materials display an improved catalytic activity. Beside the low catalytic loading (0.05–0.09 mol%) and the absence of Lewis acid co-catalysts, all the materials showed high TON values (up to 1154 for epichlorohydrin with SW-1:2). Interestingly, despite the loss of part of the polymeric coating for crumbling or peeling, the activity increases upon recycling of the materials, and this behaviour was ascribed to their change in morphology, which led to materials with higher surface areas and with more accessible catalytic sites. Transmission electron microscopy analysis, along with different experiments, have been carried out in order to elucidate these findings.

Carbon nanotubes have been covalently functionalized with catechol moieties through the formation of the corresponding aryl radicals obtained by reacting 4‐aminocatechol with isoamyl nitrite. The functionalized multiwalled carbon nanotubes have been in turn used to immobilize Pd(II) ions on its surface forming catechol‐Pd complexes, which were reduced to Pd nanoparticles (NPs). The so‐obtained hybrid material has been characterized by means of thermogravimetric analysis coupled with differential scanning calorimetry (TGA‐DSC), X‐ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). This latter technique allowed to estimate the nanoparticle size (5.7±2.8 nm) whereas a palladium loading of 20.3 wt % has been found by inductively coupled plasma optical emission spectroscopy (ICP‐OES). The carbon nanotube‐catechol‐Pd hybrid was used as catalyst in two C−C coupling reactions, namely Suzuki and Heck reactions, resulting recyclable for at least 9 times in the latter process. During the reuse Pd nanoparticles increase their dimension to 19.3±11.7 nm.