Unveiling the role of Ni in Ru-Ni oxide for oxygen evolution: Lattice oxygen participation enhanced by structural distortion

Introducing Ni in Ru oxide is a promising approach to enhance the catalytic activity for the oxygen evolution reaction (OER). However, the role of Ni (which has a poor intrinsic activity) is not fully understood. Here, a RuNiOx electrode fabricated via a modified dip coating method exhibited excellent OER performance in acidic media, and neutral media for CO2 reduction reaction. We combined in-situ/operando X-ray absorption near-edge structure and on-line inductively coupled plasma mass spectrometry studies to unveil the role of the Ni introduced in the Ru oxide. We propose that the Ni not only transforms the electronic structure of the Ru oxide, but also produces a large number of oxygen vacancies by distorting the oxygen lattice structure at low overpotentials, increasing the participation of lattice oxygen for OER. This work demonstrates the real behavior of bimetallic oxide materials under applied potentials and provides new insights into the development of efficient electrocatalysts.11Ysciescopu