Atomically Dispersed Dual-Metal Sites Showing Unique Reactivity and Dynamism for Electrocatalysis

Abstract

The real structure and in situ evolution of catalysts under working conditions are of paramount importance, especially for bifunctional electrocatalysis. Here, we report asymmetric structural evolution and dynamic hydrogen-bonding promotion mechanism of an atomically dispersed electrocatalyst. Pyrolysis of Co/Ni-doped MAF-4/ZIF-8 yielded nitrogen-doped porous carbons functionalized by atomically dispersed Co–Ni dual-metal sites with an unprecedented N8V4 structure, which can serve as an efficient bifunctional electrocatalyst for overall water splitting. More importantly, the electrocatalyst showed remarkable activation behavior due to the in situ oxidation of the carbon substrate to form C–OH groups. Density functional theory calculations suggested that the flexible C–OH groups can form reversible hydrogen bonds with the oxygen evolution reaction intermediates, giving a bridge between elementary reactions to break the conventional scaling relationship.

Tunable metal–organic frameworks assist in catalyzing DNAzymes with amplification platforms for biomedical applications

“…83 The in situ integration of bimetallic sites into a stable MOFs achieves the effect of elongating the active sites, attaining a high charge capacity, and tunable electrochemical activity. 84 A bimetallic–organic framework with different metals could alter their synergistic effects. Doping the second metal site and optimizing the molar ratio of the two metals can exploit the previous charge difference between the two atoms and expand the charge transfer.…”

Enhancing Electrocatalytic Kinetics via Synergy of Co Nanoparticles and Co/Ni–N4–C- and N-Doped Porous Carbon

“…19,20 Porous architecture and active catalytic sites can be further optimized via the Ni ions isomorphism substitution of ZIF-67. 21,22 Due to the existence of N−M−N bond, the formation of Co−N−C and Ni−N−C can be realized in ZIF derivatives by pyrolysis and etching. 23,24 Furthermore, our previous report proved that yeast cell is a microorganism containing rich N species functional groups for the anchorage of transition metal ions through the formation of M−N−C bonds.…”

“…Efficient synergistic assembly can be realized by utilizing the designable substrate with porous architecture for promoting mass transport and exposing more active sites. − Co-based zeolitic imidazolate framework–67 (ZIF-67) hybrids can fully facilitate mass transport and expose active catalytic sites because of their large surface area and high porosity, which contribute to favorable catalytic performance. , Porous architecture and active catalytic sites can be further optimized via the Ni ions isomorphism substitution of ZIF-67. , Due to the existence of N–M–N bond, the formation of Co–N–C and Ni–N–C can be realized in ZIF derivatives by pyrolysis and etching. , Furthermore, our previous report proved that yeast cell is a microorganism containing rich N species functional groups for the anchorage of transition metal ions through the formation of M–N–C bonds . Its biomineralization resulted in the formation of an excellent 3D carbon matrix coupled with ZIF-67 crystals. , Therefore, it is theoretically feasible to optimize the 3D structure of Ni-substituted ZIF-67 through yeast biomineralization and to realize the assembly of the Co/Ni–N 4 –C coupled with CoNPs; nevertheless, this synergistic principle has not been experimentally evidenced.…”

Engineering Fe-N4 Electronic Structure with Adjacent Co-N2C2 and Co Nanoclusters on Carbon Nanotubes for Efficient Oxygen Electrocatalysis

“…Transition metal-nitrogen moieties supported on carbon-based materials represent a unique class of atomically dispersed metal catalysts with high electrical conductivity [ 5 ]. They are among the most promising candidates to efficiently catalyze a wide range of electrochemical processes, such as hydrogen evolution/oxidation reactions (HER/HOR), CO 2 /CO reduction, oxygen reduction reaction (ORR), and oxygen evolution reaction (OER) [ 6 – 9 ].…”