A Bi-functional Cobalt and Nitrogen Co-doped Carbon Catalyst for Aerobic Oxidative Esterification of Benzyl Alcohol with Methanol and Oxygen Reduction Reaction

Heterogeneous M-N-C Catalysts for Aerobic Oxidation Reactions: Lessons from Oxygen Reduction Electrocatalysts

“…Co appears to be privileged for this reactivity on the basis of screening studies, which evaluated benzyl alcohol methyl esterification over a range of M-N-C­(iv) catalysts (M = Co, Fe, Cu, V, Cr, Ni, Mn) and M-N-C­(i) catalysts (M = Fe, Mn, Co Cu). Co-N-C catalysts competent for esterification have been synthesized by a variety of methods noted in Figure a, including (i), ,,,, (ii), (iii), , (iv), and (v). ,, These studies have observed CoO x nanoparticles, ,,,, metallic Co nanoparticles ,, (often with N–C shells ,,,,, ), and an absence of large metal aggregates that suggests the presence of mononuclear CoN x species. , Quantitative relationships between active site structures and reactivity have not been established.…”

“…Mechanistic pathways involving the oxidation of alcohol to aldehyde followed by hemiacetal formation and oxidation to the ester were proposed based on analogy with known homogeneous chemistry and the observation of aldehydes as byproducts . Some studies ,,, have suggested that a surface-bound superoxide radical anion is involved based on lower yields in the presence of the free-radical scavenger butylated hydroxytoluene and EPR signals for 5,5-dimethyl-1-pyrroline N -oxide after radical capture; however, this evidence shows only the formation of radical species but not their abundance or catalytic relevance. The dearth of well-defined rate data and limited mechanistic understanding of the elementary steps involved in catalysis hamper the development of structure–reactivity relationships for esterification with M-N-C catalysts.…”

“…68,71,77 These studies have observed CoO x nanoparticles, 60,67,69,74,77 metallic Co nanoparticles 60,74,77 (often with N−C shells 62,67,68,71,72,76 ), and an absence of large metal aggregates that suggests the presence of mononuclear CoN x species. 73,75 Quantitative relationships between active site structures and reactivity have not been established.…”

Atomically dispersed cobalt–nitrogen–carbon catalysts for efficient oxidative esterification of aromatic alcohols

“…23,26,27 Moreover, it is still uncertain whether Co SACs, Co NPs, Co 3 O 4 or their assemblies are the real active sites, and the catalytic mechanism for such a reaction has obvious shortcomings and deficiencies. [28][29][30][31][32][33][34] Decoupling them to design and develop catalysts with a single active site and a well-defined structure to deeply study the reaction mechanism of non-noble metal catalyzed oxidative esterification of aromatic alcohols will help us to understand the catalytic path in essence. [35][36][37][38][39][40] In view of the above considerations, we attempted to eliminate the interference of other potential active sites and develop non-noble metal singleatom catalysts (SACs) to elucidate the reaction mechanism of oxidative esterification of alcohols.…”

A COF template-derived mesoporous CeO2-supported Au nanoparticles catalyst for the oxidative esterification of benzaldehydes and benzyl alcohols

“…At this point, the direct one-pot oxidative esterification of alcohols or aldehydes with molecular oxygen is an ideal method. 9–11…”