Boride-derived oxygen-evolution catalysts

Abstract

Metal borides/borates have been considered promising as oxygen evolution reaction catalysts; however, to date, there is a dearth of evidence of long-term stability at practical current densities. Here we report a phase composition modulation approach to fabricate effective borides/borates-based catalysts. We find that metal borides in-situ formed metal borates are responsible for their high activity. This knowledge prompts us to synthesize NiFe-Boride, and to use it as a templating precursor to form an active NiFe-Borate catalyst. This boride-derived oxide catalyzes oxygen evolution with an overpotential of 167 mV at 10 mA/cm2 in 1 M KOH electrolyte and requires a record-low overpotential of 460 mV to maintain water splitting performance for over 400 h at current density of 1 A/cm2. We couple the catalyst with CO reduction in an alkaline membrane electrode assembly electrolyser, reporting stable C2H4 electrosynthesis at current density 200 mA/cm2 for over 80 h.

Co–Fe–B Nanochain Electrocatalysts for Oxygen Evolution at High Current Density

“…Previous density functional theory calculations suggests that Fe enhances the number of active sites and also stabilizes these active sites . Along with this, the introduction of boron allows for the formation of new active phases, such as the Co or Fe phase, in the pristine framework, which increases the electrocatalytic activity toward OER. , …”

“…58 Along with this, the introduction of boron allows for the formation of new active phases, such as the Co or Fe phase, in the pristine framework, which increases the electrocatalytic activity toward OER. 59,60 4. CONCLUSIONS In this study, we reported the simple and scalable fabrication of amorphous, 1D, Co−Fe−B nanochains using sodium borohydride as a reducing agent.…”

Topotactic BI3-assisted borodization: synthesis and electrocatalysis applications of transition metal borides

“…5 For OER, different metal borides have been evaluated but these studies are limited to alkaline conditions. 6,[19][20][21][22]31 Alkaline OER currently has lower technological importance as all current industrial membrane-based electrolyzers operate in acidic media due to restrictions on ionconductive membranes. 17 IrO 2 is state-of-the-art acidic OER catalysts, but is not sustainable due to the scarcity of Ir.…”

“…20 However, metal borides show good OER stability in general and treating Ni 3 B powders with concentrated hydrochloric acid results in no detectable changes, making such borides good candidates for use in acidic conditions. 21,22 In this work, we investigated the use of Ni suggest that the addition of Ni 3 B as a supporting material can be beneficial to reduce use of…”

Shining Light on Anion-Mixed Nanocatalysts for Efficient Water Electrolysis: Fundamentals, Progress, and Perspectives

“…Nevertheless, the large-scale commercialization of noble metals for water electrolysis is severely hindered by their scarcities and instability in electrolytes at high potentials. Given this, transition metal (TM)-based oxides, carbides, nitrides, sulfides, phosphides, chalcogenides, hydroxides, halides, alkoxides, and borides/borates have been explored [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38]. Unfortunately, most of these materials exhibit a low catalytic performance, impecunious electronic conductivity, passivation, and dissolution under strongly acidic conditions, hindering their practical application [21,22,39].…”