Correlating Oxygen Evolution Catalysts Activity and Electronic Structure by a High-Throughput Investigation of Ni_1-y-zFe_yCr_zO_x.

ABSTRACT: High-throughput characterization by soft X-ray absorption spectroscopy (XAS) and electrochemical characterization is used to establish a correlation between electronic structure and catalytic activity of oxygen evolution reaction (OER) catalysts. As a model system a quasi-ternary materials library of Ni_1-y-zFe_yCr_zO_x was synthesized by combinatorial reactive magnetron sputtering, characterized by XAS, and an automated scanning droplet cell. The presence of Cr was found to increase the OER activity in the investigated compositional range. The electronic structure of Ni^II and Cr^III remains unchanged over the investigated composition spread. At the Fe L-edge a linear combination of two spectra was observed. These spectra were assigned to Fe^III in O_h symmetry and Fe^III in T_d symmetry. The ratio of Fe^III O_h to Fe^III T_d increases with the amount of Cr and a correlation between the presence of the Fe^III O_h and a high OER activity is found.

SUBMITTER: Schwanke C 

PROVIDER: S-EPMC5347035 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature