Controllable Synthesis,characterizations And Electro-catalysis Study Of Platinum Based Trimetallic Nanocrystals

At present,platinum nanocrystals are widely used in direct alcohol fuel cells because of their good catalytic activity for alcohols,but the reserves of platinum are rare and expensive,the disadvantage of poisoning easily limit their further application in direct alcohol fuel cells.Therefore,it is urgent to improve the catalytic performance of Pt nanocrystals.As we all know,the catalytic activity of the catalyst is very closely related to its morphology,size,structure and the spatial distribution of elements.However,due to the different reduction potential of different metal ions,it is necessary to control the reduction rate of different kinds of metal ions in the synthesis process of nanocrystals to form alloy structures.Platinum based nanocrystals were prepared by hydrothermal synthesis of platinum and other two metals.Compared with platinum nanocrystals and platinum based nanocrystals,it not only had better catalytic activity and ability of resistance poisoning,but also reduced the consumption of platinum.Using ascorbic acid as the reducing agent,cetyltrimethylammonium chloride as structure-director,citric acid as auxiliary agent,chloroplatinic acid,potassium chloropalladite,cupric chloride and nickel chloride as metal precursor,super pure water as solvent,by using hydrothermal synthesis method,the controllable and homogeneous porous components are prepared successfully by using hydrothermal synthesis method.The trimetallic Pt Pd Cu and Pt Ni Cu nanocrystals were dispersed in ethanol after centrifugation and save as nanocrystals ink.In the standard three electrode electrolytic cell,we test the electrocatalytic oxidation performance of the small organic molecules such as methanol and ethanol.The Pt Pd Cu and Pt Ni Cu trimetallic nanocrystals showed the catalytic activity and stability of Pt Cu,Pt Pd and other binary platinum based nanocrystals and commercial Pt black.Among them,Pt Pd Cu nanocrystals exhibit superior catalytic activity and stability,their durability is also higher than commercial Pt black.After 1000 cycles of cyclic voltammetry test,the catalytic activity of Pt Pd Cu nanocrystals is 2.4 times,1.8 times and 3 times of commercial Pt black for methanol,ethanol and glycol,respectively.After three hours chronoamperometry test,the Pt Ni Cu nanocrystals catalytic performance were 9.8 and 2.7 times than the commercial Pt black,in methanol and ethanol,and the structure of Pt Ni Cu nanocrystals did not change too much.