Functionalization of Carbon Nanotubes with Nickel Cyclam for the Electrochemical Reduction of CO2

Abstract

The exploitation of molecular catalysts for CO electrolysis requires their immobilization on the cathode of the electrolyzer. As an illustration of this approach, a Ni-cyclam complex, with a cyclam derivative functionalized with a pyrene moiety, was synthesized, shown to be a selective catalyst for CO 2 electroreduction to CO and immobilized on a carbon nanotube-coated gas diffusion electrode by using a non-covalent binding strategy. The as-prepared electrode is efficient, selective, robust for electrocatalytic reduction of CO 2 to CO. Very high turnover numbers (ca. 61460) and turnover frequencies (ca. 4.27 s -1 ) were enabled by the novel electrode material in organic solventwater mixtures saturated in CO 2 . This material provides an interesting platform for further improvement.

Nickel selenide as an efficient electrocatalyst for selective reduction of carbon dioxide to carbon-rich products

“…The head-space gas was collected after 1 h of CO 2 -RR experiment at a fixed potential (−0.1 V, −0.25 V, −0.6 V, −0.9 V vs. RHE) and was injected into the GC-TCD column. Only H 2 was detected as a gaseous product at higher applied potential (>−0.6 V) and no other gaseous product like CO or CH 4 , commonly observed with previously reported catalysts, 16,19,30,[34][35][36][37][38][39][40][41][42] were detected. The amount of hydrogen gas produced was dependent on the applied potential and increased with increasing cathodic potential (FE = 0%, 0%, 0.22%, 0.56%, 1.27% at −0.1, −0.25, −0.6, −0.9 and −1.3 V, respectively).…”

Copper(ii) and zinc(ii) complexation withN-ethylene hydroxycyclams and consequences on the macrocyclic backbone configuration

“…Ligands composed of cyclam (1,4,8,11-tetraazacyclotetradecane) are widely studied for the coordination of transition metal ions, as they often form stable and inert chelates. [1][2][3][4][5][6][7][8] They are of increasing relevance in many applications for environmental or medicinal purposes. The introduction of additional moieties such as lipophilic or hydrophilic chains 6,9,10 or a chromophoric group, [11][12][13] often through N-functionalization, allows the tuning of the properties of the ligands, which can be also grafted on a solid support 14 or attached to a targeting biomolecule.…”

Complexation of C-Functionalized Cyclams with Copper(II) and Zinc(II): Similarities and Changes When Compared to Parent Cyclam Analogues

“…1,2 Transition metal ions belong to the large panel of cations that are efficiently chelated by these ligands, often when functionalized to offer six coordination sites. These chelates are widely used for several applications in medicine, 1,3 catalysis, and environmental sciences, 4 depending on the nature of the central metal ion. Among the three macrocyclic backbones mentioned above, cyclam is the most adapted to the complexation of transition metals.…”