Tensile strain improves perovskites for sustainable energy production

The electrochemical oxygen evolution reaction, or OER, is a highly important process in many sustainable energy production methods, such as water electrolysis and fuel cells. However, the four-electron process is too slow for cost-effective and scalable OER. Alternative electrocatalysts, such as easily tunable perovskite oxides, could lower the reaction energy barrier and accelerate reaction kinetics necessary for improved OER.

Guan et al. presented a novel way to tune perovskite oxides to improve OER performance. The researchers induced a tensile strain in perovskites with a thermochemical reduction method. Unlike previous tuning strategies, this method proved simpler and was found to significantly improve OER performance across a number of typical perovskites.

The technique was initially tested on a one-dimensional perovskite compound with a large, flexible structural unit. Analysis of the perovskite showed the chemical-induced strain optimized the solid-liquid tension, making the hydrophobic compound adsorb liquid reactants.

Spectroscopic measurements indicated the method created oxygen vacancies in the saturated face-sharing Co-O motifs of the perovskite, allowing it to become hydrophilic. Additional computational results demonstrated important physiochemical properties that are helping the team further understand the effects of the strategy.

“We hope this work can offer meaningful and systematic insights into the rational material design and in-depth understanding for many emerging energy and environmental applications, including water electrolysis, fuel cells and rechargeable metal-air batteries,” said co-author Zongping Shao. “We expect to excite the immediate interest of a wide audience of scientists who are interested in the energy storage and conversion systems for many emerging applications.”

Source: “A universal chemical-induced tensile strain tuning strategy to boost oxygen-evolving electrocatalysis on perovskite oxides,” by Daqin Guan, Jian Zhong, Hengyue Xu, Yu-Cheng Huang, Zhiwei Hu, Bin Chen, Yuan Zhang, Meng Ni, Xiaomin Xu, Wei Zhou, and Zongping Shao, Applied Physics Reviews (2022). The article can be accessed at https://doi.org/10.1063/5.0083059 .