铅修饰纳米多孔铂催化剂对甲酸氧化的电活性（英文）

Lead Modified Nanoporous Platinum Electro-Catalysts for Formic Acid Oxidation

用合适金属修饰的铂催化剂能够显著增强其对甲酸氧化的电活性.本文以水热法制备了钛负载的纳米多孔铂电极(nanoPt/Ti),然后采用循环伏安法,通过扫描不同的周数(n),用适量的铅对nanoPt/Ti电极进行修饰,得到一种新型的铅修饰的纳米多孔铂电极(nano Pb_((n))-Pt/Ti).采用循环伏安(CV)、计时电流和计时电位法研究其对对甲酸氧化的电活性.CV结果显示nanoPt/Ti和nanoPb_((n))-Pt/Ti电极对甲酸氧化表现出较高的催化活性,并且nanoPb_((20))-Pt/Ti电极对甲酸氧化的起始电位为-0.06 V,相比nanoPt/Ti电极的起始电位(0.06 V),明显有所负移.此外,nanoPb_((20))-Pt/Ti电极的第一个氧化峰电流密度为12.7 mA·cm^(-2),远远大于nanoPt电极(4.4 mA·cm^(-2));计时电流显示在电位为0.1 V时,在0.5 mol·L^(-1)H_2SO_4+1 mol·L^(-1 )HCOOH溶液中,nanoPb_((20))-Pt/Ti电极达到稳定时的电流为8.09 mA·cm^(-2),是nanoPt电极的60倍,表明铅修饰的nanoPt/Ti对甲酸氧化的电活性急剧增加;在1.5mA、2 mA、2.2 mA和2.5 mA下的计时电位结果表明,nanoPb_((20))-Pt/Ti电极上甲酸氧化过程表现出显著的电化学振荡,且和nano Pt/Ti电极相比,振荡现象能持续更长的时间,说明nanoPb_((20))-Pt/Ti电极具有更强的表面抗毒化能力.

Platinum（Pt）catalysts modified by other suitable metals significantly enhance their electrochemical activities for formic acid oxidation.In this work,a titanium-supported nanoporous network platinum（nano Pt/Ti）electrode was prepared using a hydrothermal method.The as-prepared nano Pt/Ti electrode was modified with a certain amount of lead by using cyclic voltammetry for different scan cycle numbers（n）,namely,n=10,15,20 and 30,to synthesize the novel lead-modified nanoporous Pt（nano Pb（（n））-Pt/Ti）electrodes.Electro-oxidation of formic acid on these electrodes was studied with cyclic voltammetry（CV）,chronoamperometry and chronopotentiometry in sulfuric acid solution.CV curves showed that both nano Pt/Ti and nano Pb（（n））-Pt/Ti electrodes displayed high electrocatalytic activities for formic acid oxidation,and the onset potential of formic acid oxidation on the nano Pb（（20））-Pt/Ti electrode was-0.06 V,which was more negative than that on the nano Pt/Ti electrode（0.06 V）.In addition,the first oxidation peak current density on the nano Pb（（20））-Pt/Ti electrode was 12.7 mA·cm^-2,which was far larger than that on the nano Pt electrode（4.4 mA·cm^-2）.Chronoamperommetric data at 0.1 V in 0.5 mol·L^-1H2SO4＋1 mol·L^-1HCOOH suggested that the nano Pb（（20））-Pt/Ti electrode exhibited the stable current density of 8.09 mA·cm^（-2 ）which was 60 times higher than the nano Pt electrode,indicating the dramatic enhancement of electroactivity on the lead-modified nano Pt/Ti electrode for formic acid oxidation with comparison to the nano Pt/Ti electrode.Chronopotentiometric responses on the electrode at 1.5 mA,2 mA,2.2 mA and 2.5 mA in 0.5 mol·L^-1H2SO4＋1 mol·L^-1HCOOH revealed notable electrochemical oscillations which lasted longer time than those on the nano Pt/Ti electrode.It was demonstrated that the lead-modified nano Pb（（20））-Pt/Ti electrode presented the most significant enhancement on surface anti-poisoning ability.