Construction Of Noble Metal Clusters Anchored On MOFs Derivatives And Their Application In Hydrogen Evolution Reaction

Hydrogen is a highly efficient and environmentally friendly energy medium because of its high theoretical mass energy density(120 MJ kg^-1).Hydrogen can be obtained in high yield by electrochemical water splitting,but the development of hydrogen evolution reaction?HER?electrocatalysts that are efficient and cheap and have long-term stability is crucial to enable affordable large-scale practical applications.Pt is still deemed to be the state-of-the-art electrocatalyst for the HER because of its high catalytic activity and stability.However,because of its low abundance,Pt is expensive and this significantly hinders commercialization.Recently,much effort has focused on developing alternatives to Pt catalysts,e.g.,catalysts based on transition metals and their compounds?sulfides,selenides,and phosphides?,for the HER.Such catalysts have excellent catalytic activities,but their synthesis is environmentally unfriendly and complex.In addition,these catalysts suffer from high overpotentials and low current densities,and their performances are inferior to those of Pt-based catalysts.Their practical applications in the HER are therefore limited.The design of novel catalysts with high activities,stabilities and low noble metal loading is therefore needed to enable low-cost practical hydrogen generation.In this work,we innovatively designed and synthesised Ru metal clusters combined with single cobalt atoms anchored on MOFs-derived nitrogen-doped carbon?Ru@Co-SAs/N-C?materials with the assistance of Metal-Organic Frameworks.Our synthetic strategy includes two steps:?1?a pyrolysis process of predesigned bimetallic ZnCo-ZIF and the formation of single cobalt atoms anchored on nitrogen-doped carbon?Co-SAs/N-C?,followed by?2?chemical reduction of the ruthenium metal salt to Ru metal clusters in the presence of Co-SAs/N-C.Based on the synergistic effect between Ru clusters and single cobalt atoms,Ru@Co-SAs/N-C exhibits an outstanding HER electrocatalytic activity.Specifically,Ru@Co-SAs/N-C only needs 7 mV overpotential at 10 mA cm^-2 in 1 M KOH solution,which is much better than commercial 20 wt%Pt/C?40 mV?catalyst.Density functional theory?DFT?calculations further reveal the synergy effect between surface Ru nanoclusters and Co-SAs/N-C toward hydrogen adsorption for HER.Additionally,Ru@Co-SAs/N-C also exhibits excellent catalytic ability and durability under acidic and neutral media.The two-step hydrothermal synthesis method was applied to precious metal platinum.The Pt clusters size was adjusted by changing the temperature during the reduction process to form the Pt metal clusters combined with single cobalt atoms anchored on nitrogen-doped carbon materials?Pt@Co-SAs/N-C?,and low Pt catalysts with excellent HER performance were obtained.When Pt@Co-SAs/N-C obtained 10 mA cm^-22 current density in 1 M KOH and 0.5 M H₂SO₄ electrolytes,only 6 mV and 8 mV Overpotentials were needed,respectively.It also demonstrates a good electrochemical hydrogenation and stability in neutral conditions.The present study opens a new avenue towards the design of noble metal clusters/single cobalt atoms heterostructures with outstanding performance toward HER and beyond.