在无还原剂存在下,氯化钯在Vulcan XC-72碳粉( C)、多壁碳纳米管( MWCNT)和碳球( CM)等碳质材料表面上自发还原为金属钯,从而得到相应的钯纳米颗粒( Pd-C、Pd-MWCNT和Pd-CM)。用阳离子表面活性剂十六烷基三甲基溴化铵( CTAB)对这些碳质材料修饰后,采用同样的自发还原方法分别制备出Pd/CTAB-C、Pd/CTAB-MWCNT和Pd/CTAB-CM催化剂。结果表明,CTAB修饰后的MWCNT明显增加了钯纳米颗粒的自发沉积量,粒径大约为9 nm,而在MWCNT上沉积的纳米Pd粒径为19 nm。 Pd/CTAB-MWCNT在碱性条件下对乙醇氧化的电流密度达到44.2 mA·cm-2,与其他碳载体负载的Pd纳米催化剂相比,对乙醇氧化具有强而稳定的电催化活性。
Pd nanoparticles ( Pd-NPs) were deposited on the surface of Vulcan XC-72 carbon black ( CB) , multi-walled carbon nanotubes ( MWCNTs) and carbon spheres ( CSs) by the spontaneous reduction of PdCl2 with oxygen-functional groups on the car-bon surfaces to produce catalysts for the electrochemical oxidation of ethanol. These carbons were also modified with a cationic sur-factant ( hexadecyltrimethyl ammonium bromide, CTAB) and subsequently used as supports for the deposition of Pd nanoparticles using the spontaneous reduction method. SEM, TEM and XRD were used to characterize their structures. Pd-NPs with a size of ca. 9 nm were obtained on the surface of the CTAB-modified MWCNTs. The amount of Pd-NPs spontaneously deposited on the CTAB-MWCNTs is much larger than that on the MWCNTs, CB or CSs. The Pd/CTAB-MWCNTs exhibit a higher anodic peak current density of 44. 2 mA·cm-2 in cyclic voltammetry, indicating a better electrocatalytic activity for ethanol oxidation than the other cat-alysts.
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