Structure-activity relationship of doped-nitrogen (N)-based metal-free active sites on carbon for oxygen reduction reaction

Thermal Annealing Effect of Co−N−C/Carbon Nanotube on the Electrochemical Oxygen Reduction Reaction

“…Thus, defects are already formed in the first step pyrolysis process, and increasing pyrolysis time reduces the defects by forming more graphitic degree; defects from NÀ C bonding configuration are tuned during the second pyrolysis process in which more pyridinic-N is formed. Though the contribution of Ncontaining active sites to the ORR is still in debate, [16] it is no doubt that all the work attribute the ORR activity to the doping effects of the heteroatoms, which changes the charge and spin densities of carbon atoms, and the doping atoms serve as active centers for oxygen molecules adsorption and activation. [17] Generally, graphitic-N and pyridinic-N are proposed more active to ORR with different functions, graphitic-N content determined the limiting current density and pyridinic-N content improved the onset potential for ORR.…”

Copolymer‐Induced Intermolecular Charge Transfer: Enhancing the Activity of Metal‐Free Catalysts for Oxygen Reduction

“…In most cases, the carbon networks with the incorporation of higher electronegative nitrogen dopants (i.e., planar pyridinic nitrogen) will present an increase in positive charge density, which is claimed as the active configuration for ORR . However, the other forms of pyrrolic and graphitic nitrogen are also intensely deliberated to be the active origins for ORR instead of pyridinic nitrogen . The huge controversy originates from the fact that their gross doping generated through pyrolysis treatment is essential, which leads to the uncontrollable structure and the unavoidable coexistence of valid/invalid doping .…”

“…[7,[9][10][11] However,t he otherf orms of pyrrolic and graphitic nitrogena re also intensely deliberated to be the activeo rigins for ORR instead of pyridinic nitrogen. [12][13][14] The huge controversy originates from the fact that their gross doping generated through pyrolysis treatment is essential, which leads to the uncontrollable structurea nd the unavoidable coexistence of valid/invalid doping. [15,16] Therefore, it is urgent to determine pyrolysis-free synthetic strategies to control active sites in welldefined structures.…”

PdAu alloy nanoparticles supported on nitrogen-doped carbon black as highly active catalysts for Ullmann coupling and nitrophenol hydrogenation reactions

“…[32][33][34] As reported, nitrogen doping is considered one of the most effective ways to further modify the properties of carbon materials, where the more negativelycharged nitrogen atoms can help to gain interactions between the active components and the substrates. [35][36][37][38][39] The lone pair electrons in the nitrogen atoms can also act as Lewis base sites, which can partly modulate the electronic properties, basicity and hydrophilicity of carbon black. 40,41 To the best of our knowledge, few works have been reported about the welldispersed nitrogen-doped carbon black (NCB) supported bimetallic PdAu NPs in organic catalysis.…”