Phys.org September 1, 2021
Electrolysis could produce fuels and chemical feedstocks more sustainably and reduce the use of fossil fuels. But the sluggish pace of oxygen evolution reaction (OER) has been a bottleneck to improving its efficiency. A team of researchers in the US (Stanford University SLAC National Accelerator Laboratory, Lawrence Berkeley National Laboratory, UC Berkeley, NIST) used operando X-ray absorption spectroscopy measurements to demonstrate that the origin of water oxidation activity of IrNiFe SACs is the presence of highly oxidized Ir single atom in the NiFe oxyhydroxide under operating conditions. They showed that the optimal water oxidation catalyst could be achieved by systematically increasing the oxidation state and modulating the coordination environment of the Ir active sites anchored atop the NiFe oxyhydroxide layers. The resulting catalyst is better than most of the iridium-based catalysts known to date, the researchers reported. They said this new atom-anchoring system provides an ideal model for probing and establishing the connection between catalysts and their support structures for a variety of electrocatalytic reactions…read more. Open Access TECHNICAL ARTICLEÂ
The preparation route to Ir single-atom on NiFe oxyhydroxides and atomic structure characterizations of NiFeIr by HAADF-STEM. Credit: PNAS September 7, 2021, 118 (36) e2101817118Â