Preparation And Oxygen Reduction Performance Of Supported Pt-based Bimetallic Alloy Nanoparticles

Population increase,urbanization,and rising living standards have rapidly increased global energy consumption and environmental burdens in the last half century.Energy consumption is expected to continue to grow dramatically in the coming years along with associated environmental issues.Although there is no universal solution to solve all energy and environment-related problems,catalysis certainly plays a critical role in the design of efficient processes and systems able to maximize the value of starting materials while minimizing waste generation and energy requirements.Oxygen reduction reaction(ORR)is a very critical part of the catalytic system.Fuel cells(FCs)and metal-air batteries(MABs)are new types of energy storage devices,and their efficiency is directly affected by ORR efficiency.Therefore,in order to improve the performance of these two new battery devices,the ORR process should be accelerated first.The platinum-based catalyst(Pt/C)supported by ultrafine platinum nanoparticles on a carbon black substrate is currently the most advanced and effective ORR catalyst.However,due to its cost and stability issues,commercial Pt/C catalysts are facing huge difficulties in the large-scale application of energy devices.Therefore,reducing the cost of the platinum catalyst and improving the activity and stability of the platinum catalyst are problems that we urgently need to solve.The structure and interaction of heterogeneous atoms can induce changes in surface properties and reactivity through ligand,strain,and integration effects.Therefore,alloying Pt with other metals(transition metals Fe,Co,Ni,etc.or Group Ⅲ metals Ga,etc.),while reducing the amount of precious metal Pt,can also prepare a series of bimetallic Pt bases with enhanced catalytic activity alloy.In addition,in order to further reduce the amount of platinum,effectively reduce agglomeration,and increase the number of catalyst active sites,a suitable carrier can also be used to immobilize homogeneous and monodisperse nanoparticles.Among them,carbon-based with porous structure and tunable surface chemistry is a good choice.This paper studies the annealing-free preparation of PtCo alloy(PtCo@NMC)and PtGa alloy(PtGa@NMC)nanoparticles supported on nitrogen-doped mesoporous carbon.The above two catalysts are used in ORR electrocatalysis in alkaline and acidic electrolytes.Compared with the industrial Pt/C catalyst,the half-wave potential(E1/2)of the PtCo@NMC catalyst has increased to 0.93-0.94 V(Vs.RHE),and the positive shift is about 45 mV,while the PtGa@NMC catalyst has a positive shift of about 30 mV.And further proved the excellent long-term durability of the two catalysts through chronoamperometry(CA)and accelerated durability tests(ADTs).In addition,the PtCo@NMC catalyst was selected as the cathode material to carry out the assembly and testing of zinc-air batteries(ZABs),demonstrating the practical application of the catalyst in electrochemical energy devices.