摘要 : The self supporting three dimensional (3D) nanoporous PdAg alloy (NP-PdAg) foams have been prepared by a simple one-step dealloying melt-spun Al-Pd-Ag ribbons in a 20 wt.% NaOH aqueous solution at 90 degrees C for 1.5 h. The struc... 展开 The self supporting three dimensional (3D) nanoporous PdAg alloy (NP-PdAg) foams have been prepared by a simple one-step dealloying melt-spun Al-Pd-Ag ribbons in a 20 wt.% NaOH aqueous solution at 90 degrees C for 1.5 h. The structure is advantageous to the diffusion and removal of the intermediate products and the transmission of the methanol molecules. The NP-PdAg foams exhibit better electrocatalytic performance than the NP-Pd foam toward the methanol oxidation in potassium hydroxide (KOH) solution. The optimal atomic ratio of Pd to Ag in the NP-PdAg foams is 1:1, and its electrocatalytic activity is about 2.6 times that of the NP-Pd foam. The significant improvement in the electrocatalytic performance is attributed to the addition of a moderate amount of Ag. In the whole electrocatalytic process, Ag can provide OHads to oxidize the intermediate products on the surface of active Pd sites into carbon dioxide or other cleaning products. Also, the Ag can increase electrochemical active surface area and the adsorption energy of Pd to methanol molecules and OHads. These significantly prevent the accumulation of poisoning intermediates on the surface of Pd and quickly release more active Pd sites. 收起