Nitrite Reduction on Bismuth Modified Pt(111) Surfaces in Different Electrolytic Media

Abstract

In this paper, the electrocatalytic enhancement of the Pt(111) surface modified with Bi adatoms towards nitrite reduction and the quantification of the catalytic effect of different adatom coverages are reported. The results were obtained in acidic and neutral media using cyclic voltammetry and in situ infrared spectroscopy measurements and show that the presence of irreversible adsorbed bismuth on Pt(111) electrodes catalyzes nitrite reduction. The presence of the foreign adatom shifts nitrite reduction to potentials as high as 0.80-0.60 V vs RHE, coinciding with the potential at which Bi undergoes its redox surface reaction. Different coverages of Bi on the surface were prepared, revealing that the activity increases with the amount of Bi until its coverage approaches half the saturation of the maximum surface blockage. For higher coverages, the activity decreases steeply, resulting in a volcano-like curve. The spectroelectrochemical experiments show that the main product of nitrite reduction at these high potentials is N 2 O.

Tailoring the catalytic activity of electrodes with monolayer amounts of foreign metals

“…Nowadays, typical implementation strategies for engineering electrocatalysts with submonolayer and monolayer amounts of foreign atoms involve modification of model single crystal surfaces, [113][114][115][116][117][118] extended polycrystalline surfaces 104 and nanoparticles. 37,119,120 One can distinguish (i) ''pure'' surface science approaches in which samples are prepared under ultra-high vacuum (UHV), 121,122 and (ii) approaches which use electrochemical steps, [123][124][125][126] including underpotential deposition.…”

WO2 nanoparticles with oxygen vacancies: a high-efficiency electrocatalyst for the conversion of nitrite to ammonia

“…At present, noble metalbased catalysts show excellent electrocatalytic activity for the NO 2 − reduction reaction (NO 2 − RR); however, natural scarcity and high value will limit their extensive industrial applications. [22][23][24][25][26] Consequently, it is of great signicance to explore and develop high-performance earth-abundant NO 2 − RR catalysts. [27][28][29][30][31][32][33][34] Monoclinic tungsten dioxide (WO 2 ) possesses a rutile-like crystal structure consisting of octahedral WO 6 units with distorted characteristics, giving it a unique metallic conductivity.…”

Powering denitrification: the perspectives of electrocatalytic nitrate reduction

“…) and N 2 O for Pt-Bi. 102,103 Molecular catalysts: macrocycles and enzymes Composites, (supra)molecular or bio-inspired electrocatalysts for denitrification have briefly been reviewed elsewhere. 30 Often, they are developed for highly sensitive electrochemical nitrate sensors 16,[104][105][106][107][108][109] and so mechanistic insight is typically not pursued.…”