非晶态Pt壳层Ni@Pt纳米粒子的甲醇电催化氧化动力学

Methanol Electro-oxidation Kinetics on Ni@Pt Nanoparticles Coated by Amorphous Metal

通过连续两步化学还原法制备了非晶态金属壳层的Ni@Pt纳米粒子,并通过球差校正高分辨透射电镜、XRD、EDS及XPS对其微观结构及组成进行了表征。运用电化学方法研究了硫酸溶液中甲醇在该纳米粒子上的电化学反应动力学过程。结果表明:采用这种方法制备出了非晶态金属Pt包覆的Ni@Pt核壳型纳米粒子,平均粒径约为12nm,壳层厚度约为1～2nm;非晶态壳层Pt纳米粒子上的塔菲尔斜率最小值为0.075,比晶态纳米粒子的低;同时甲醇反应级数最大值可达到0.60,比晶态纳米粒子的高。这说明非晶态金属是高活性的甲醇电氧化催化剂。

Ni@Pt nanoparticles were synthesized in continuous two-ste p chemical reduction method,and their composition and microstructure were chara cterized through aberration-corrected HRTEM,XRD,EDS,XPS,and methanol elect ro-oxidation kinetics on Ni@Pt nanoparticles in sulfuric acid solution was studied through electro-chemical method.The results show tha t,Ni@Pt core-shell nano-particles coated by amorphous platinum were synthesiz ed in continuous two-step chemical reduction method,the average diameter was a bout 12 nm,and the average shell thickness was about 1～2 nm;the minimum Tafel slope for amorphous metal was 0.075,which was lower than that for crystalli ne metal;and the maximum value of methanol reaction order was 0.60,which was higher than that for crystalline metal.The results illustrate that the methanol electro-catalytic activity of amorphous metals was high.