Devisable POM/Ni Foam Composite: Precisely Control Synthesis toward Enhanced Hydrogen Evolution Reaction at High pH

Abstract

Polyoxometalates (POMs) are promising catalysts for the electrochemical hydrogen production from water owing to their high intrinsic catalytic activity and chemical tunability.H owever,p oor electrical conductivity and easy detachment of the POMs from the electrode cause significant challenges under operating condition. Herein, as imple onestep hydrothermal methodi sr eportedt os ynthesize as eries of Dexter-Silverton POM/Ni foam composites (denoted as NiM-POM/Ni; M = Co, Zn, Mn), in which the stable linkage between the POM catalysts and the Ni foam electrodes lead to high activity for the hydrogen evolution reaction (HER).Amongthem, the highest HER performance can be observed in the NiCo-POM/Ni, featuring an overpotential of 64 mV (at 10 mA cm À2 ,v s. reversible hydrogen electrode), and aT afel slope of 75 mV dec À1 in 1.0 m aqueous KOH. Moreover, the NiCo-POM/Ni catalyst showedahigh faradaic efficiency % 97 %f or HER. Post-catalytic of NiCo-POM/Ni analyses showedv irtually no mechanical or chemical degradation. The findings propose af acile and inexpensivem ethodt o designs table and effective POM-based catalysts for HER in alkaline water electrolysis.

Surface Atom Regulation on Polyoxometalate Electrocatalyst for Simultaneous Low-Voltage H2 Production and Phenol Degradation

“…Compared with POM with large size, small-sized POM usually possesses more excellent stability in alkaline media. Up to now, some POM compounds have been reported, which remain stable in alkaline media. ,, Compared with them, Strandberg type (NH 4 ) 4 [(HO 2 C 3 H 4 PO 3 ) 2 Mo 5 O 15 ] possesses higher stability in alkaline media due to its small size. Furthermore, in NiP 2 Mo 5 , (NH 4 ) 4 [(HO 2 C 3 H 4 PO 3 ) 2 Mo 5 O 15 ] is strengthened by [Ni­(bipy) 2 (H 2 O)] 2+ .…”

“…Up to now, some POM compounds have been reported, which remain stable in alkaline media. 30,35,65 2+ . The modification of POM by coordination complex can enhance stability.…”

Benefits of Organo‐Aqueous Binary Solvents for Redox Supercapacitors Based on Polyoxometalates

“…Further potential decrease down to −1.6 V vs. Ag/Ag + results in hydrogen evolution, which is higher in the case of 1 M LiNO 3 /H 2 O‐DMSO than in 1 M LiNO 3 /H 2 O‐DMSO+HPOM (Figure c). This can be explained by enhanced overpotential for hydrogen evolution at the AC owing to the favorable adsorption of POMs, which modifies the hydrogen evolution potential . Even if less hydrogen is evolved in 1 M LiNO 3 /H 2 O‐DMSO+HPOM, a part of it might be aided by the protons which come from POMs (not only from the free water), and its effects on the aging of the full cell will be discussed later.…”

A Series of Polyoxometalate-Based Metal–Bis(pyridyl-tetrazole) Complexes with High Electrocatalytic Activity for Hydrogen Evolution Reaction in Alkaline and Acid Media

“…Song et al have introduced Dexter−Silvertontype POMs on Ni foam, which were adopted as catalysts for HER. 22 A high HER performance was achieved, reaching a current density of 10 mA•cm −2 at an overpotential of 64 mV and a Tafel slope of 75 mV•dec −1 in aqueous KOH. The stable linkage between POM and Ni foam gave rise to the high activity.…”

“…The introduction of POM-based materials directly for HER catalysts was rarely reported. Song et al have introduced Dexter–Silverton-type POMs on Ni foam, which were adopted as catalysts for HER . A high HER performance was achieved, reaching a current density of 10 mA·cm –2 at an overpotential of 64 mV and a Tafel slope of 75 mV·dec –1 in aqueous KOH.…”