Bi-defect sites are highly effective for CO2 reduction (CO2RR) to formic acid, yet most catalytic surfaces predominantly feature inert, non-defective Bi sites. To overcome this limitation, herein, tensile strain is introduced on wholescale non-defective Bi sites. Under rapidthermal shock, the Bi-based metal organic framework (Bi-MOF-TS) shows weakened Bi–O bonds and produced tiny Bi clusters. During electrochemical reduction, these clusters create numerous continuous vacancies, inducing weak tensile strain over a large range of surrounding non-defective Bi sites. The excel file provides the source data for our research.