本文選題：模板法　切入點(diǎn)：碳化鎢　出處：《江西理工大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：碳化鎢具有類鉑催化性能和較強(qiáng)的抗中毒能力,但其催化活性遠(yuǎn)低于鉑等貴金屬催化劑。為尋找改善碳化鎢催化性能的技術(shù)方法,本文使用模板法制備納米級(jí)碳化鎢前驅(qū)體,以乙醇/甲醇混合液為還原劑和碳源,成功制備了納米級(jí)碳化鎢和碳化鎢/碳管納米復(fù)合材料,并其電催化性能進(jìn)行了評(píng)價(jià)。論文主要研究了碳化鎢和碳化鎢/碳管納米材料的制備方法及工藝條件。首先從碳納米管的純化與分散入手,高溫處理和酸洗有利于去除碳納米管中的雜質(zhì),超聲分散選用乙二醇為分散劑有利于碳納米管又快又好的分散。其次,是在碳納米管純化與分散的基礎(chǔ)上,以碳納米管為模板制備鎢酸/碳納米管前驅(qū)體,優(yōu)化工藝參數(shù)為:溫度為100oC,碳納米管與鎢酸鈉的摩爾質(zhì)量比為1:14。最后為還原碳化步驟,該步驟選擇的碳源通入溫度為600 o C,碳源中乙醇濃度為10%,以0.2 m L/min的速率升至1000 o C保溫1小時(shí)。采用SEM、XRD、差熱以及HRTAM等分析手段對(duì)樣品進(jìn)行了表明,結(jié)果表明,本工藝可以制備出純相WC,WC顆粒粒徑小于300 nm。在上述實(shí)驗(yàn)的基礎(chǔ)上以乙二醇還原法制備的WC/Pt和WC/CNTs/Pt催化劑作為甲醇的電催化材料,比較了兩種材料電化學(xué)性能。實(shí)驗(yàn)結(jié)果表明,兩種催化劑材料均具有與Pt及Pt電極相類似的電催化氧化性能,即甲醇電催化氧化是通過(guò)解離吸附產(chǎn)物和反應(yīng)中間體雙途徑機(jī)理完成。兩種催化劑材料均有較好的電催化活性,但在酸性體系下,復(fù)合材料對(duì)甲醇的電催化活性略高。
[Abstract]:Tungsten carbide has the catalytic activity of platinum-like and anti-poisoning, but its catalytic activity is much lower than that of noble metal catalyst such as platinum. In order to find a technical method to improve the catalytic performance of tungsten carbide, the nanometer tungsten carbide precursor was prepared by template method. Nanocrystalline tungsten carbide and tungsten carbide / carbon tube nanocomposites were successfully prepared using ethanol / methanol mixture as reducing agent and carbon source. The preparation methods and process conditions of tungsten carbide and tungsten carbide / carbon nanotubes were studied. Firstly, the purification and dispersion of carbon nanotubes were introduced. High temperature treatment and acid pickling are helpful to remove impurities in carbon nanotubes (CNTs), and the ultrasonic dispersion with ethylene glycol as dispersant is beneficial to the rapid and good dispersion of CNTs. Secondly, it is based on the purification and dispersion of CNTs. Tungsten acid / carbon nanotube precursor was prepared by using carbon nanotubes as template. The optimized process parameters are as follows: temperature is 100oC, molar ratio of carbon nanotubes to sodium tungstate is 1: 14.The last step is reduction carbonization. The carbon source input temperature is 600o C, the ethanol concentration in the carbon source is 10 鈩，

本文編號(hào)：1603840