High-performance manganese and nitrogen codoped carbon (Mn–N–C) oxygen reduction electrocatalyst from Mn²⁺ coordinated sodium alginate

Abstract

The research on low-cost, high-performance non platinum group metal (PGM) oxygen reduction reaction (ORR) catalysts is of great significance for the rapid promotion of fuel cells’ practical applications. In this work, Mn-N-C catalyst with outstanding activity was prepared through using hydrogel formed by coordination of sodium alginate (SA) and Mn2+ as the precursor. During the preparation process g-C3N4 was added to improve the surface area enrich the pore structure of catalysts, as well as to function as the nitrogen source. Compare with commercial Pt/C catalyst, the optimum Mn-N-C catalyst possesses extraordinary ORR activity in alkaline electrolytes, with half-wave potential (E1/2) of 0.90 V. In addition, the Mn-N-C catalyst also displays exceptional stability in alkaline and acidic electrolytes, much superior to Pt/C catalyst.

Homogeneous catalysis of dioxygen reduction by molecular Mn complexes

“…For the purposes of this perspective, we are excluding Cu-based systems, 26 heterogeneous systems based on molecular Mn active sites, and single atom Mn catalysts, but we direct interested readers to a number of relevant reviews and articles on heterogeneous and immobilized Mn-based catalysts for the ORR. [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43]…”

Anchored Ru clusters on a lignin/algae carbon aerogel as an efficient bifunctional catalyst for water splitting

“…This porous carbon carrier with relatively large specific surface area and excellent electrical conductivity not only provides efficient channels for reactants to reach the catalyst surface, but also has a positive impact on effective electron and mass transport, as well as dispersion and stability of alloy nanoparticles. 32 Moreover, introducing S into carbon aerogels can modify the environment for active metals. 33 This adjustment not only optimizes the adsorption energy of the intermediate *H in the HER, but also reduces the energy barrier for the rate-determining step.…”

Recent Progress and Prospects of Manganese–Nitrogen–Carbon Electrocatalysts for Oxygen Reduction Reaction

“…materials have recently become focuses of electrocatalysis research. 25,34,41 Metal−nitrogen (M−N x ) groups anchored on carbon substrates exhibit distinctive physicochemical properties, including extensive surface area, excellent electrical conductivity, and an adjustable coordination environment. 42,43 The Fe−N x and Co−N x sites are susceptible to attack by reactive oxygen species, including intermediate hydroxyl radicals, during the ORR (Fenton reaction), leading to reduced durability.…”

“…60,86 Pyrolysis is the preferred technique for synthesizing Mn−N−C catalysts. 41,49 During the pyrolysis process, unregulated thermal migration of metal atoms occurs at elevated temperatures. 41,49,88 To overcome this challenge and achieve a homogeneous distribution of Mn atoms on the carbon material, innovative synthesis strategies tailored for Mn−N−C synthesis by pyrolysis are required.…”