动态氢气泡/牺牲铜模板法制备蜂窝AuPtCu电催化剂用于甲酸氧化

微/纳多孔金属材料具有高比表面积等优点,在电化学等领域广受关注.本工作通过动态氢气泡模板法,在镀金玻璃碳电极(Aupla/GCE)上电沉积三维蜂窝状多孔纳米AuPtCu (3DHPN-AuPtCu)复合材料,再阳极溶出Cu,制备了3DHPN-AuPt Cu/Aupla/GCE.采用循环伏安法(CV)、金相显微镜、扫描电子显微镜、能量色散谱和电感耦合等离子体-原子发射光谱等手段表征了相关修饰电极.所制3DHPN-AuPt Cu/Aupla/GCE在含0.2 mol/L HCOOH的0.5 mol/L H2SO4水溶液中,电催化氧化甲酸的峰电流密度为12.5 m A·cmPt^-2(CV,-0.3~1.0 V, 50 m V/s),优于有关对照电极和很多已报道的Pt复合物修饰电极,表明通过这种动态氢气泡/牺牲铜双模板法可制备出电催化性能优异的金属蜂窝结构.

Preparation of Honeycomb-structured AuPtCu Electrocatalyst by Dynamic Hydrogen Bubble and Sacrificial Cu Templates for Oxidation of Formic Acid

Improving the performance of electrocatalytic formic acid oxidation is the key issue to develop high-performance direct formic acid fuel cells(DFAFC). Pt-based and Pd-based materials are the important electrocatalysts for formic acid oxidation. Micro/nano-porous metal materials are widely concerned in the electrochemistry field due to the high specific electrode-surface area. The dynamic hydrogen bubble template(DHBT) method has been widely used for preparing the three-dimensional honeycomb-like porous nano-metals(3 DHPNMs). However, as far as we know, the use of a sacrificial metal template to prepare the 3 DHPNMs with improved performance for the electrocatalytic oxidation of small organic molecules has not been reported. Herein, a three-dimensional honeycomb-like porous nano-AuPtCu(3 DHPN-AuPtCu)composite was electrodeposited on a gold-plated glassy carbon electrode(Aupla/GCE) by the DHBT method, followed by anodic stripping of Cu to yield a 3 DHPN-AuPtCu/Aupla/GCE. The relevant modified electrodes were characterized by cyclic voltammetry(CV), metallographic microscopy, scanning electron microscopy(SEM), energy dispersive spectroscopy and inductively coupled plasma-atomic emission spectrometry. The SEM results clearly revealed that the use of the sacrificial Cu template can modulate the metal-honeycomb structure, and the 3 DHPN-AuPtCu/Aupla/GCE can thus possess the better micro/nano-porous structure and the improved electrocatalytic performance than a Cu-template-free3 DHPN-AuPt/Aupla/GCE. In our opinion, the simultaneous electrodeposition of Cu can intervene in the electrodeposition of Au and Pt, and thus a new structure with more active sites exposed and the electrocatalysis performance improved can be obtained after the anodic stripping of electrodeposited Cu. As a result, the 3 DHPN-Au PtCu/Aupla/GCE exhibited high anti-poisoning nature and high stability, because many discontinuous Pt atoms on this electrode can suppress the formation of adsorption-state COads during the electrocatalytic oxidation of formic acid. The electrocatalytic oxidation peak current density on 3 DHPN-AuPtCu/Aupla/GCE in 0.5 mol/L aqueous H2SO4 containing 0.2 mol/L HCOOH was 12.5 m A·cmPt^-2(CV,-0.3~1.0 V, 50 m V/s), which is superior to the control electrodes and many reported Pt-based electrocatalysis electrodes. The suggested double-template method for preparing honeycomb-structured micro/nano-porous metal materials with improved performance has the potential for wider electrocatalysis and electroanalysis applications.