The Preparation And Electrocatalytic Properties Of Pt-Cu Nanoporous Structure

With increasing energy crisis and environmental pollution,the development of new clean energy is without delay.The hydrogen evolution reaction?HER?and oxygen reduction reaction?ORR?involved in electrochemical processes are the two most promising energy conversion and storage methods.Therefore,the design of high performance HER and ORR electrocatalysts is particularly important for improving electrochemical energy conversion and storage performance.At present,Pt is still one of the catalysts with the highest electrocatalytic activity of HER and ORR.However,its expensive price,very low storage capacity and poor stability and anti-toxicity greatly limit the practical application of Pt.The Pt-Cu alloy,through the synergistic effect between the components enhance its catalytic activity and reduce the cost of the catalyst,so it has more practical value in the field of catalysis.In this paper,Pt-Cu alloy nanocatalyst was synthesized by using CuCl as the sacrificial template at room temperature,with salt as the precursor and without any surfactant.The paper also discussed the synthesis mechanism of Pt-Cu alloy and achieved the regulation of different components of the alloy by changing the precursor concentration.The samples with different alloy ratios were then electrochemically tested and compared to commercial platinum carbon.The results showed that the initiation potential and half-wave potential of ORR were all increased with the decreased ratio of Pt to Cu.In addition,the Pt-Cu alloy had a good methanol tolerance,which was better than commercial Pt/C catalyst.In order to further improve the catalytic performance,dealloying treatment,as a favorible method to synthesis porous structure materials,had been used by us to create more pores,which increased the overall surface area of the catalyst and may have more active sites exposed.The dealloying process eliminated the unstable components of copper and then formed the pore walls by the rest of the noble metals,as a result of the formation of nanoporous structures.Through the HER performance test,it was found that the overpotential?33 mV?at 10 mA cm^-2 reached the commercial catalyst level and its tafel slope?28.5 mV/dec?was smaller than that of the commercial catalyst?30.0 mV/dec?,which indicated that the reaction is a fast kinetic process.In order to further study its stability in the catalytic process,the stability test was also carried out.The LSV polarization curves under different cycle times and I-T curves showed that the porous Pt-Cu alloy nanocatalysts had strong stability,indicating that they have the same potential value as commercial platinum carbon.