P and S dual-doped graphitic porous carbon for aerobic oxidation reactions: Enhanced catalytic activity and catalytic sites

Abstract

A highly porous graphitic carbon material, dually-doped with P and S, was studied as a metal free catalyst for aerobic oxidation reactions. Catalytic mechanism studies suggest that the active centers, originated from P-and S-doping, additively/synergistically catalyze the aerobic oxidation of benzylic alcohols but with different pathways. For the first time, catalytic centers stemming from S-doping were experimentally identified to be exocyclic S species (C-S-C, sulfur out of the carbon ring), which are different from those proposed for electrochemical oxygen reduction reactions (ORR) with a 4epathway and oxygen evaluation reactions (OER). Notably, all the catalytic sites from both P and S doping share a similar "protruding out" pyramid structure, which is in contrast to the planar structure of the catalytic sites in Nor B-doped graphitic materials. The unique geometric structure of the catalytic sites can minimize substrate steric hindrance effects, endowing the P, S co-doped catalysts with a wide substrate scope and functional group tolerance. Furthermore, the unambiguous distinguishment of the catalytic sites from those in OER and ORR provides valuable guidance for designing and developing carbon materials with controlled active sites to satisfy different catalytic applications.

Cu2S‐Cu3P Nanowire Arrays Self‐Supported on Copper Foam as Boosting Electrocatalysts for Hydrogen Evolution

“…After sulfuration and phosphatation, the Cu 2 S‐Cu 3 P NW arrays show no obvious morphological changes, but form a relatively rougher surface with a coarse top similar to the sulfurated or phosphated samples (Figure S3 and S4, Supporting Information). The rough structures possibly result from the phosphide and sulfide doping effect as reported, which will increase the specific surface area, facilitate mass transfer, and consequently enhance the electrocatalytic activity. After sulfuration, the morphology is still preserved very well (Figure S3a,b, Supporting Information).…”

“…It is known that double element‐doped material is more competitive than single element‐doped material in terms of electrocatalysts. Patel et al proved that P and S heteroatoms synergism of carbon could lower the activation energy for the benzyl alcohol oxidation reaction and showed better catalytic performance than the only P‐doped carbon electrocatalyst . Dou et al found that S and P co‐doped atoms not only destroyed the electron permeability of sp 2 carbon in graphene and enhanced the electrocatalytic activity for oxygen reduction, but they also interacted with each other to provide favorable synergetic effects…”

Heteroatom‐Enhanced Metal‐Free Catalytic Performance of Carbocatalysts for Organic Transformations

“…P=O and P−OH groups accomplished the catalytic cycle under aerobic condition. In succession, the author achieved a P and S dual‐doped graphitic porous carbon with a “protruding out” pyramid structure in the same synthetic method for aerobic alcohols oxidation . For the first time, catalytic centers stemming from S‐doping were experimentally identified to be exocyclic S species (C−S−C, sulfur out of the carbon ring).…”

“…In succession, the author achieved a P and S dual-doped graphitic porous carbon with a "protruding out" pyramid structure in the same synthetic method for aerobic alcohols oxidation. [63] For the first time, catalytic centers stemming from S-doping were experimentally identified to be exocyclic S species (CÀ SÀ C, sulfur out of the carbon ring). Very recently, Chen et al [64] definitely found the critical catalytic role of the C 3 PO species based on the reaction result and DFT calculations.…”

Improved porosity and ionic sorption capacity of carbon particles prepared by spray pyrolysis from an aqueous sucrose/NaHCO3/TEOS solution

“…Porous carbon materials (PCMs) have gained much attention in the research areas of energy storage devices, [13][14][15] catalysts, [16][17][18] and adsorptive separation [19][20][21][22] due to their unique properties including excellent electrical conductivity, large specic surface area and chemical stability. The required properties of PCMs are different depending on their application area.…”