The Study In Preparation And Characterization Of Palladium-copper Alloy Nanomaterials And Electrocatalytic Performance For Oxidation Of Formic Acid And Methanol

Direct liquid fuel cells have received extensive attention and research as a high energy density,low pollution,safe and efficient energy conversion device.However,the high cost and low performance of the anode catalyst of direct liquid fuel cells hinder its large-scale commercial application.At present,the design of anode catalysts mainly focuses on reducing the amount of precious metals,resisting CO poisoning,and improving catalytic activity and stability.Therefore,this paper takes precious metal Pd as research object,on the one hand,Pd is alloyed with low-priced and abundant Cu metal.It is found that the catalytic performance of the catalyst strongly depends on the regulation of its composition and size;on the other hand,The PdCu/CeO₂ catalyst was prepared by loading PdCu alloy nanoparticles on CeO₂nanorods.The interaction between the support cerium oxide and palladium-copper alloy nanoparticles and its effect on the electrocatalytic oxidation of formic acid and methanol were investigated.The main contents are as follows:?1?The PdCu alloy was synthesis by co-reduction of Pd and Cu precursor through using oleylamine?OAm?solvent as both a reducing and protective agent.PdCu alloy nanoparticles with different compositions were prepared by changing the molar ratio of Pd and Cu precursors.The preparation of PdCu alloy nanoparticles with different sizes is achieved by controlling the addition rate of precursors.The nanocatalyst was characterized by using HRTEM,XRD,XPS,EDS elemental analysis.The electrocatalytic performance of PdCu alloy nanocatalyst for the oxidation of formic acid was studied.The dependence of the catalytic activity of PdCu alloy nanoparticles on the composition and size of the catalyst was analyzed.?2?CeO₂ nanorods were prepared by hydrothermal synthesis,and PdCu alloy nanoparticles were coupled with CeO₂ nanorods by wet chemical method.By characterization of TEM,XRD and XPS,it was observed that CeO₂ NRs induced significant compressive strain of PdCu alloy nanoparticles through the interaction of CeO₂?220?and PdCu?111?crystal planes,which further broadened the d-band bandwidth and reduced The d-belt center.The catalyst's resistance to CO poisoning was improved by these effects.The CeO₂-supported PdCu catalyst showed greatly enhanced catalytic activity for FAOR and MOR.The catalytic activity of PdCu/CeO₂-1 for formic acid electrooxidation was 1.72 A/mg,which was 7.5 times for commercial Pd/C?0.23 A/mg?.It was found that the increased catalytic activity is attributed to the synergistic catalysis by increased Pd oxide on PdCu surface and oxygen vacancies on CeO₂ NRs.This study specifically reveals the mechanism of the enhanced catalytic activity of metal catalysts supported on CeO₂ nanorods,and can provide a reference for the rational design of high performance anode catalysts for fuel cells.