Electrocatalytic Performance Of Silver Modified Porous Carbon Structures

With the development of human society,the energy shortage is one of the major problems facing by human beings.Traditional energy sources such as coal,oil and natural gas are limited.Therefore,the development of new energy which has high energy density and little effect on the environment become the focus of research both at home and abroad.Fuel cells and metal-air batteries have the advantage of high energy efficiency and non-polluting,they have become the new hotspot research of energy.Currently,the most commonly used is still the commercial Pt/C catalyst.But the Pt-based catalysts suffer from limited reserves,high cost,limited stability,which severely impede the application of fuel cells and metal-air batteries.Porous carbon-metal composite materials with high catalytic activity of oxygen reduction reaction are stable in the alkaline solution,which are often used to replace precious metal catalysts.The porous carbon composite materials,which can improve conduction property of the substrate and ionic,and the synergy effect of biomass and metal,greatly improving the catalytic activity.In this study,Ag@ZIF-8 and Ag-NAC samples were synthesized by one-step method,and the preparation process was explored.The synthesized samples were tested by SEM,TEM,HRTEM,XPS,XRD,EDS,etc.And the morphology,structure,phase composition and elements of the catalyst were characterized.The electrocatalytic performance of the oxygen reduction reaction(ORR)was tested using a rotating disk electrode technique.The catalyst was then assembled into an air electrode to study the constant current discharge in the zinc air battery.Through characterization and electrochemical testing of the prepared samples,we proposed the ORR catalytic mechanism from the porous nature of Ag,pyridinium and matrix.The Ag-modified porous carbon catalyst has excellent ORR performance and has a good charge and discharge voltage in a zinc-air battery,and has good zinc-air battery stability.In summary,the silver-porous carbon structure is a potential alternative to platinum carbon,an excellent oxygen reduction electrocatalyst.