Premium
Boosting Water Oxidation through In Situ Electroconversion of Manganese Gallide: An Intermetallic Precursor Approach
Author(s) -
Menezes Prashanth W.,
Walter Carsten,
Hausmann Jan Niklas,
BeltránSuito Rodrigo,
Schlesiger Christopher,
Praetz Sebastian,
Yu. Verchenko Valeriy,
Shevelkov Andrei V.,
Driess Matthias
Publication year - 2019
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201909904
Subject(s) - intermetallic , manganese , in situ , boosting (machine learning) , materials science , metallurgy , chemistry , chemical engineering , computer science , artificial intelligence , engineering , alloy , organic chemistry
For the first time, the manganese gallide (MnGa 4 ) served as an intermetallic precursor, which upon in situ electroconversion in alkaline media produced high‐performance and long‐term‐stable MnO x ‐based electrocatalysts for water oxidation. Unexpectedly, its electrocorrosion (with the concomitant loss of Ga) leads simultaneously to three crystalline types of MnO x minerals with distinct structures and induced defects: birnessite δ‐MnO 2 , feitknechtite β‐MnOOH, and hausmannite α‐Mn 3 O 4 . The abundance and intrinsic stabilization of Mn III /Mn IV active sites in the three MnO x phases explains the superior efficiency and durability of the system for electrocatalytic water oxidation. After electrophoretic deposition of the MnGa 4 precursor on conductive nickel foam (NF), a low overpotential of 291 mV, comparable to that of precious‐metal‐based catalysts, could be achieved at a current density of 10 mA cm −2 with a durability of more than five days.