Development of tender/soft X-ray absorption spectroscopy to operando measurements

Operando X-ray absorption fine structure (XAFS) measurements are a very powerful tool to study catalytic materials under reaction conditions. Therefore, hard X-ray XAFS in the high-energy region has often been used to observe the electronic structure and local structure of catalytic materials. On the other hand, tender and soft X-ray XAFS measurements in the low-energy region, which can study light elements, have attracted much attention in recent years. In this article, we will introduce the setup and examples of operando XAFS observations using tender and soft X-rays. (author)