MWCNTs-Supported Pd(II) Complexes with High Catalytic Efficiency in Oxygen Reduction Reaction in Alkaline Media

Abstract

We report here the remarkable catalytic efficiency observed for two Pd(II) azamacrocyclic complexes supported on MWCNTs towards ORR. Beyond a main (>90%) 4 eprocess and onset potential close to or better than those of commercial Ptelectrodes, the multi-walled carbon nanotubes (MWCNTs) functionalization strategy, aiming at chemically defined Pd(II)-based catalytic centers, allowed the half-cell to exceed PEM fuel cell reference/target mass activity efficiency set by US Department of Energy (DOE) for 2020 (440 mA/mg PGM at 0.9 V vs Reversible Hydrogen Electrode (RHE)).Fuel cells are promising candidates for sustainable future energetic technology. Oxygen reduction reaction (ORR) allows to release the chemical energy stored in the vector molecule H 2 in the form of electrical work without producing any waste but innocuous H 2 O molecules. For this reason, oxygen reduction is regarded as a highly strategic reaction, upon whose efficiency the near-future energy storage and powering technology depend.

Stabilisation of Exotic Tribromide (Br3−) Anions via Supramolecular Interaction with a Tosylated Macrocyclic Pyridinophane. A Serendipitous Case

“…It was later in the spotlight for its ability to form metal complexes [6][7][8], but its wider success was achieved thanks to its utilisation as a scaffold for the preparation of new materials that have proven effective in a variety of applications. Indeed, L derivatives decorated with different hanging functionalities have been studied for several biomedical (MRI contrast agents [9][10][11][12], antiproliferative treatments [13][14][15][16], radiotherapy [17,18], enzyme mimicking [19,20] and antioxidant activity [21][22][23]), chemosensing [24][25][26][27] and catalytic [28][29][30][31][32][33] applications. Very recently, (MRI contrast agents [9][10][11][12], antiproliferative treatments [13][14][15][16], radiotherapy [17,18], enzyme mimicking [19,20] and antioxidant activity [21][22][23]), chemosensing [24][25]…”

“…Anion-π interactions were also found to play an important role in the formation of highly organised polyiodide complexes [44,45] and iodide based permutable organised frameworks (POF) [46] with a pyridinium-based ligand such as Stoddart's blue box (BB, cyclobis(paraquat-p-phenylene)). (MRI contrast agents [9][10][11][12], antiproliferative treatments [13][14][15][16], radiotherapy [17,18], enzyme mimicking [19,20] and antioxidant activity [21][22][23]), chemosensing [24][25][26][27] and catalytic [28][29][30][31][32][33] applications. Very recently, it has been shown that L and its N-trimethylated derivative are capable of stabilising iodine-dense three-dimensional networks that might be relevant for crystal engineering purposes and the design of solid-state conductors [34].…”

“…It was later in the spotlight for its ability to form metal complexes [ 6 , 7 , 8 ], but its wider success was achieved thanks to its utilisation as a scaffold for the preparation of new materials that have proven effective in a variety of applications. Indeed, L derivatives decorated with different hanging functionalities have been studied for several biomedical (MRI contrast agents [ 9 , 10 , 11 , 12 ], antiproliferative treatments [ 13 , 14 , 15 , 16 ], radiotherapy [ 17 , 18 ], enzyme mimicking [ 19 , 20 ] and antioxidant activity [ 21 , 22 , 23 ]), chemosensing [ 24 , 25 , 26 , 27 ] and catalytic [ 28 , 29 , 30 , 31 , 32 , 33 ] applications. Very recently, it has been shown that L and its N-trimethylated derivative are capable of stabilising iodine-dense three-dimensional networks that might be relevant for crystal engineering purposes and the design of solid-state conductors [ 34 ].…”

Sensing Zn2+ in Aqueous Solution with a Fluorescent Scorpiand Macrocyclic Ligand Decorated with an Anthracene Bearing Tail

“…Scorpiand type aza-macrocyclic ligands, that is aza-macrocyclic ligands with coordinating tails [1], and their metal complexes have attracted considerable interest thanks to the numerous uses they have been tested for, including but not limited to various biomedical applications [2,3] (MRI contrast agents [4,5], radioisotopes complexation and radiolabelling [6][7][8][9], radiotherapy [10][11][12][13][14], chelation therapy [15][16][17], antiproliferative treatments [18][19][20][21], enzyme mimicking [22][23][24][25][26][27][28][29]), catalysis [30][31][32][33][34][35][36] and chemosensing [37][38][39][40][41][42][43].…”

Palladium Supported on Carbon Nanotubes as a High-Performance Catalyst for the Dehydrogenation of Dodecahydro-N-ethylcarbazole

“…In addition, CNTs can endow beneficial interactions between support and metal NPs, thus improving the catalytic activity. As is well known, the synthesis method for Pd NPs, such as doping or through a supramolecular strategy, an alcohol reduction method, is another key factor for improving the dehydrogenation performance of the catalysts [35,[41][42][43][44]. Fang et al [42] have successfully synthesized Pd/rGO using ethylene glycol as a reductant for the hydrogen production of dodecahydro-N-ethylcarbazole.…”