Preparation Of Cobalt And Nitrogen Co-Doped Carbon Catalysts And The Application In ORR

With the global warming and the decreasing of fossil energy,the development of green and clean energy has been paid more attention by people.Fuel cell is a kind of energy conversion device which can convert the chemical energy to the electrical energy by electrochemical reaction.It is very important to develop efficient and low-cost catalysts for large-scale commercialization of fuel cells because the sluggish oxygen reduction reaction(ORR)needs limited resources and expensive platinum as catalysts to accelerate.As the Co-N-C catalyst is not only cheap,but also has the close electrocatalytic activity to that of Pt-based catalysts.Based on the above reasons,a series of Co-N-C oxygen reduction catalysts were prepared,which mainly include the following three aspects:(1)Co and N co-doped carbon fiber catalyst was successfully synthesized by electrospinning polyvinylpyrrolidone and cobalt nitrate hexahydrate.The experimental results show that the Co-N-C-87.6 catalyst not only had the oxygen reduction catalytic performance closed to that of commerical Pt/C catalyst,but also showed good stability and methanol tolerance.(2)Co and N co-doped mesoporous carbon sphere catalyst was successfully synthesized by electrospinning and hard template method.And the polyacrylonitrile,polyvinylpyrrolidone,fumed silica and cobalt acetate tetrahydrate were materials.The experimental results show that Co-N-C-37.5 catalyst has good catalytic activity for oxygen reduction.By studying different cobalt content catalysts,we found that Co-N-C-37.5 catalyst not only had a large specific surface area(419 m2 g-1),but also had good oxygen reduction performance.(3)Co and N co-doped carbon nanosheet catalyst was successfully synthesized by foaming agent expansion method.And the zinc nitrate hexahydrate、cobalt nitrate hexahydrate、lactose monohydrate and deionized water were materials.The experimental results show that the Co-N-C-43.8 catalyst has better oxygen reduction catalytic activity than commercial Pt/C catalyst,and the onset potential,half wave potential and limiting current density were higher by 31 m V,3 m V and 3 m A cm-2,respectively.At the same time,it also showed excellent stability and methanol tolerance.