Yy. Yang et al., Surface modification and electrocatalytic properties of Pt(100), Pt(110), Pt(320) and Pt(331) electrodes with Sb towards HCOOH oxidation, ELECTR ACT, 46(28), 2001, pp. 4339-4348
Behaviors of irreversibly adsorbed Sb adatoms on Pt(100), Pt(110), Pt(320)
and Pt(331) single crystal surfaces and electrocatalytic properties of the
modified electrodes towards formic acid oxidation were investigated. It was
determined that Sb adatoms are stable at potentials below 0.45 V (SCE) on
Pt(100) and Pt(110), below 0.40 V on Pt(320), and below 0.35 V on Pt(331).
Different coverage of Sb-ad was obtained conveniently by partially strippin
g Sb-ad from saturation coverage of Sb-ad. It has demonstrated that the red
ox behaviors of Sb adatoms and the coadsorption properties of Sb-ad with H-
ad depend strongly on the orientations of the Pt single crystal electrode.
Significant catalytic effects towards HCOOH oxidation were observed on Pt s
ingle crystal electrodes modified with Sb adatoms, which consist of (1) the
inhibition of dissociative adsorption of HCOOH, (2) the enhancement of oxi
dation current, and (3) the negative shift of oxidation potential that was
measured about 220 mV on Pt(110)/Sb, 110 mV on (110) sites of Pt(320)/Sb, a
nd 100 mV on Pt(331)/Sb electrode. Neither enhancement of oxidation current
nor negative shift of oxidation potential can be observed on Pt(,100)/Sb e
lectrode. The results suggested that electronic effect is the main effect p
resented on Pt(110), Pt(320) and Pt(331) surface upon Sb modification, whil
e geometric effect is considered to the major effect on Pt(M) electrode. (C
) 2001 Elsevier Science Ltd. All rights reserved.