Regulation The Electronic Structure Of Metals By Heteroatoms To Optimize Their Electrocatalytic Performance

Nowadays,with the prominent increasingly of energy consumption and environmental pollution,developing new-type clean energy and storage devices is gaining traction.Batteries and hydrogen energy,as promising energy conversion and storage devices,have great potential in the field of new energy vehicles.ORR,OER,HER and HOR are key electrochemical reactions for fuel cells and metal-air batteries.It is highly dependent on Pt-based catalysts.Unfortunately,the high cost and poor durability of Pt have impeded widespread commercial applications of any emerging energy-conversion devices.Therefore,finding non-precious metals and low Pt catalysts is a hot topics for Current Research.Carbon nanofibers generally owns good electrical conductivity and large specific surface area.Meanwhile,one-dimensional nanostructures are widely used as support materials for catalytic active component.Moreover,doped with heteroatoms of nonmetals(such as N,P,B,S)and transition metals atoms(such as Fe,Co or Ni)can change the electronic distribution and geometric structure,further bring more structure defects.The main research works of this paper are as shown below:(1)Atomic Fe-N-C Catalysts with Multiple Active Sites Obtained by Synchronized Sulfuration for oxygen reduction reaction and high performance Zinc Air Batteries.In this work,sulfuration is used to boost the activity of FexC/Fe,forming an improved system,“FeNC-S-Fe,C/Fe"”,for catalysis involving oxygen.Meanwhile,DFT theoretical calculations show that the improvements in the activity from the synergistic coupling of the effects of the FeNx active sites with those of the FexC/Fe species and those of S-containing species.In particular,FeNC-S-FexC/Fe exhibited excellent ORR activity(half slope potential(E1/2 of 0.821 V(vs.RHE),0.887 V(vs.RHE)in acidic and alkaline media,respectively)and durability(almost no activity decay after 10000 cycles).Interestingly,FeNC-S-Fe,C/Fe also showed excellent catalytic activity for OER.Therefore,FeCN-S-FexC/Fe can be used as a high performance bifunctional catalyst for zinc-air batteries.(2)Study on electrochemical properties of RuxB nanoparticles as hydrogen evolution catalyst in a universal pH range.The developing of cost-effective,efficient,and stable electrocatalyst for HER that can function in universal pH range is highly desirable but remains a great challenge.In this work,for the first time,we report a N-doped carbon-coated RuxB nanoparticles(Ru2B3@CNF).As expected,Ru2B3@CNF catalyst shows excellent HER performance with ultralow overpotentials of 7,41,and 58 mV to achieve 10 mA cm-2 in 1.0 M KOH,0.5 M H2SO4,and in 1.0 M PBS,respectively,which is comparable to commercial Pt/C catalyst in acidic and neutral conditions,even better than Pt/C catalyst in alkaline conditions,as well as superior durability at all pH values Our combined DFT computational results reveal that the electron-deficient B atom can contribute to the local electronic redistribution,leading to the anchoring preference effect of H*on Ru atom for Ru-B bonds in RU2B3 over Ru-Ru bonds in Ru Thus,our work highlight a new type of cheap transition-metal-based for high-efficiency HER electrocatalyst.