缺碳型介孔空心球状碳化钨制备及其对甲醇氧化的电化学行为

• 作 者: 陈赵扬 马淳安 赵峰鸣 乔芸 屠晓华
• 机 构: 浙江工业大学化材学院绿色化学合成技术国家重点实验室培育基地,
• 出 处: 化学学报
• 发表日期: 2010年04期
• 关键词: mesoporous structure:tungsten carbide methanol electro-oxidation electrocatalysi

采用喷雾干燥法制得空心球状结构偏钨酸铵,通过固定床气固反应,以CO/H2为还原碳化气氛在700～900℃下制备了介孔结构空心球状碳化钨(WC).经XRD,SEM及EDS测试表明,WC粉末样品在保持了单相WC的前提下,样品存在一个微量缺碳的原子比例,其W/C>1,且在高氢环境中WC球体表面有部分纳米颗粒依附于片状碳化钨基体上.将制备得到的WC粉末样品制成微电极,采用电化学测试技术研究了WC在硫酸介质中对甲醇的电催化氧化反应.结果表明,缺碳的介孔结构空心球状WC催化剂对甲醇氧化有着良好的电催化活性,并对动力学参数进行了研究,结果显示其反应的表观活化能为105.06kJ/mol,且其在微电极中的氧化行为受扩散控制.

Hollow ammonium meta-ammonium tungstate was prepared by spray drying method, and hollow spherical tungsten carbide (WC) with mesoporous structure was prepared by fixed-bed gas-solid reaction and CO / H2 reductive carbonation at 700-900 ℃ .After XRD, The results of SEM and EDS show that there is a trace atomic ratio of carbon missing in the WC powder sample with W / C> 1 under the precondition of keeping the single-phase WC, and some nanoparticles adhere to the WC surface in the high-hydrogen environment The WC powder sample prepared on the flaky tungsten carbide substrate was made into a microelectrode, and the electrocatalytic oxidation of WC on methanol in a sulfuric acid medium was studied by electrochemical test technique.The results showed that the carbon-free mesoporous hollow structure The spherical WC catalyst has good electrocatalytic activity for the oxidation of methanol, and the kinetic parameters were studied. The results showed that the apparent activation energy of the reaction was 105.06 kJ / mol, and its oxidation behavior in the microelectrode was controlled by diffusion.