摘要
确定了水热法制备TiO_2纳米线的最佳参数,对采用最佳参数制备的TiO_2纳米线进行碳化处理,再在其表面沉积铂得到Pt/TiC/TiO_2催化剂,研究了不同阶段产物的物相组成、化学成分和微观形貌,测试了Pt/TiC/TiO_2催化剂的催化甲醇氧化能力。结果表明:最佳水热参数为NaOH溶液浓度1 mol·L-1、水热温度160℃、水热时间20h,所得TiO_2纳米线的直径约为100nm、长度超过1μm;碳化后得到了TiC/TiO_2纳米线,沉积铂后,其表面被纳米级铂颗粒所覆盖;Pt/TiC/TiO_2催化剂催化甲醇氧化的起始氧化电位(对比Ag/AgCl)为0.34V,比Pt/TiO_2催化剂催化下的负移了约0.15V,其正扫电流密度峰值比Pt/TiO_2催化剂催化下的大8倍以上,碳化明显提高了Pt/TiO_2催化剂催化甲醇氧化的能力。
Optimal parameters of TiO_2 nanowires prepared by hydrothermal method were determined.TiO_2 nanowires prepared with the optimal parameters were treated by carbonization and surface deposited with platinum,and then the Pt/TiC/TiO_2 catalyst was obtained. The phase composition, chemical composition and micromorphology of the products in different stages were investigated,and the catalytic methonal oxidation capability of Pt/TiC/TiO_2 catalyst was tested.The results show that the optimal hydrothermal parameters were listed as follows:NaOH solution concentration of 1 mol·L-1,hydrothermal temperature of 160 ℃,and hydrothermal time of 20 h.Consequently,TiO_2 nanowires with diameter of about 100 nm and length of over 1μm were obtained.The TiC/TiO_2 nanowires were obtained after carbonization and the surface was coated with platinum nanoparticles after the deposition of platinum.The initial oxidation potential of methanol oxidation catalyzed by Pt/TiC/TiO_2 catalyst was 0.34 V(vs Ag/AgCl),about 0.15 Vnegative shift compared with that by Pt/TiO_2 catalyst,and the maximum forward current density was more than 8 times as large as that by Pt/TiO_2 catalyst.The carbonization improved the catalytic methanol oxidation capability of Pt/TiO_2 catalyst significantly.
引文
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