FORMIC-ACID OXIDATION ON PT(111) ELECTRODES MODIFIED BY IRREVERSIBLY ADSORBED SELENIUM

被引:55
作者
LLORCA, MJ
HERRERO, E
FELIU, JM
ALDAZ, A
机构
[1] Departament de Química Física, Universitat d'alacant, E-03080 Alacant
来源
JOURNAL OF ELECTROANALYTICAL CHEMISTRY | 1994年 / 373卷 / 1-2期
关键词
D O I
10.1016/0022-0728(94)03326-9
中图分类号
O65 [分析化学];
学科分类号
070302 ; 081704 ;
摘要
The irreversible adsorption of selenium on Pt(111) electrodes allows Pt(111) modified electrodes with a selenium coverage up to 0.5 to be prepared and characterized voltammetrically. Such modified electrodes have different electrocatalytic properties for formic acid oxidation than the unmodified Pt(111) electrode. Two different aspects of the formic acid oxidation reaction were studied: (i) the catalytic enhancement of formic acid oxidation with selenium coverage and the influence of the surface structure of the selenium adlayer and (ii) the inhibition of the poison formation reaction from formic acid by the presence of adsorbed selenium on the electrode surface. An increase in the catalytic activity of the modified electrode was found at selenium coverages greater than 0.20, maximum catalytic activity being achieved at a selenium coverage of 0.28. With selenium coverages higher than 0.33, the catalytic activity of the electrode diminishes. In the poison formation experiments, the poison formation reaction was inhibited by the selenium adatoms by a third-body mechanism. The complete inhibition of the poison formation reaction occurred at a selenium coverage of 0.28, the coverage at which the maximum catalytic activity was found. A relationship between the structure of the selenium adlayer and the catalytic enhancement is proposed.
引用
收藏
页码:217 / 225
页数:9
相关论文
共 18 条
[1]   ORIGIN OF ACTIVATION EFFECTS OF ACETONITRILE AND MERCURY IN ELECTROCATALYTIC OXIDATION OF FORMIC-ACID [J].
ANGERSTE.H ;
MACDOUGALL, B ;
CONWAY, BE .
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 1973, 120 (06) :756-766
[2]   EFFECT OF BI AND SN ADATOMS ON FORMIC-ACID AND METHANOL OXIDATION AT WELL DEFINED PLATINUM SURFACES [J].
CAMPBELL, SA ;
PARSONS, R .
JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS, 1992, 88 (06) :833-841
[3]  
CHANG SC, 1990, J PHYS CHEM-US, V94, P1034
[4]  
CLAVILIER J, 1989, J ELECTROANAL CHEM, V261, P113, DOI 10.1016/0022-0728(89)87130-X
[5]   HETEROGENEOUS ELECTROCATALYSIS ON WELL DEFINED PLATINUM SURFACES MODIFIED BY CONTROLLED AMOUNTS OF IRREVERSIBLY ADSORBED ADATOMS .1. FORMIC-ACID OXIDATION ON THE PT (111) - BI SYSTEM [J].
CLAVILIER, J ;
FERNANDEZVEGA, A ;
FELIU, JM ;
ALDAZ, A .
JOURNAL OF ELECTROANALYTICAL CHEMISTRY, 1989, 258 (01) :89-100
[6]   AN IRREVERSIBLE STRUCTURE SENSITIVE ADSORPTION STEP IN BISMUTH UNDERPOTENTIAL DEPOSITION AT PLATINUM-ELECTRODES [J].
CLAVILIER, J ;
FELIU, JM ;
ALDAZ, A .
JOURNAL OF ELECTROANALYTICAL CHEMISTRY, 1988, 243 (02) :419-433
[7]   ELECTROCHEMICAL ADSORPTION BEHAVIOR OF PLATINUM STEPPED SURFACES IN SULFURIC-ACID-SOLUTIONS [J].
CLAVILIER, J ;
ARMAND, D ;
SUN, SG ;
PETIT, M .
JOURNAL OF ELECTROANALYTICAL CHEMISTRY, 1986, 205 (1-2) :267-277
[8]   PULSED LINEAR SWEEP VOLTAMMETRY WITH PULSES OF CONSTANT LEVEL IN A POTENTIAL SCALE, A POLARIZATION DEMANDING CONDITION IN THE STUDY OF PLATINUM SINGLE-CRYSTAL ELECTRODES [J].
CLAVILIER, J .
JOURNAL OF ELECTROANALYTICAL CHEMISTRY, 1987, 236 (1-2) :87-94
[9]   ELECTROCHEMICAL-BEHAVIOR OF IRREVERSIBLY ADSORBED SELENIUM DOSED FROM SOLUTION ON PT(H,K,L) SINGLE-CRYSTAL ELECTRODES IN SULFURIC AND PERCHLORIC-ACID MEDIA [J].
FELIU, JM ;
GOMEZ, R ;
LLORCA, MJ ;
ALDAZ, A .
SURFACE SCIENCE, 1993, 289 (1-2) :152-162
[10]  
FERNANDEZVEGA A, 1989, J ELECTROANAL CHEM, V258, P101, DOI 10.1016/0022-0728(89)85165-4