Synthesis And Performance Of Oxygen Reduction Reaction Catalysts Based On Super Absorbent Resin

As an electrochemical energy-conversion device without combustion,fuel cell satisfies the requirements for clean,efficient,safe and reliable operation,expected to become the power source of electric vehicles,computers and other mobile devices instead of the internal combustion engine technology.However,the slow cathodic oxygen reduction reaction kinetics set the main bottleneck to achieve a large number of commercial applications.Therefore,its cathode catalyst has attracted increasely attention.Nonetheless,the state-of-the-art catalysts is based on expensive noble metal with limited reserves.As a result,developing high activity,low cost and high stability of non-precious metal catalyst is great important for the development of fuel cells.This work focus on the promising catalysts,transition metal-nitrogen doped carbon catalyst M-N-C.The superabsorbent resin polyacrylic acid-acrylamide were selected as both carbon and nitrogen sources creatively,used to prepare oxygen reduction reaction catalyst and to study performance.The main contents of this paper are as follows:(1)A simple,green and clean method of spontaneous foaming,self-dispersing and selfassembling was developed.Polyacrylic acid-acrylamide,a kind of super absorbent resin,was cleverly applied to the preparation of M-N-C catalyst without additional templates,nitrogen sources and carbon sources.A series of M-N-C catalysts with different transition metals(Fe,Co,Ni)were prepared by one-step pyrolysis,providing the further insights to investigate the best ORR active sites.The results show that in alkaline the activity order of the catalysts prepared by different metals is Co > Fe > Ni.(2)In order to further develop M-N-C catalyst,heat treatment temperature and transition metal content were investigated the effects on the activity of ORR catalysts based on Co-N-C system,providing facts and basis for further improving the catalytic performance.The results show that the optimal performance appears at 800 ? pyrolysis with low cobalt loading attributed to the abundant catalytic sites(transition metal coordination bonds and nitrogendoped carbon species).The Co-N-C catalyst exhibits an excellent electrocatalytic performance,which are comparable or superior to the commercial 20% Pt/C and reported M-N-C ORR electrocatalysts.