Precise Dual-Metal Pairs Enable Ultrafast Structural Response for CO <sub>2</sub> -to-Ethylene Photoconversion
Wentao Song, Bo Song, Yuhang Liang, Yi Zhou, Bo Wang, Wanguo Gao, Yao Wu, Ling Xia, Yong Liu, Ruquan Ye, Qian He, Tze Chien Sum, Yingfang Yao, Zhiqun Lin, Zhigang Zou, Bin Liu
Abstract
Dual-metal sites have shown great potential for high catalytic performance, owing to their synergistic effects. However, randomly distributed dual-metal sites and unidentified coordination environments make it challenging to investigate charge transfer dynamics and elucidate actual catalytic mechanisms. Herein, we report a judicious strategy to construct precisely distributed dual-metal pairs through anchoring single atoms in vacancy-rich metal–organic frameworks (MOFs), enabling ultrafast structural response for CO 2 photoreduction to ethylene. Using oxygen vacancy-rich Mil-125(Ti)-NH 2 loaded with Cu atoms as an example, low-dose real-space imaging and X-ray absorption spectra reveal the well-defined distribution of Cu–Ti dual-metal pairs, resulting in rapid charge transfer from Ti to neighboring Cu within 3.0 ps. Remarkably, a high solar-to-chemical efficiency of 0.62% with a superior electron-based selectivity of 78.3% for ethylene production from CO 2 and H 2 O is achieved. Mechanistic investigation unveils that the unique Cu–Ti bimetallic pairs induce strong d-p hybridization with *CHOCO intermediates and undergo structural self-regulation under excitation, thereby facilitating C–C coupling to proceed spontaneously. The generality of precise dual-metal pairs for the ethylene synthesis is also realized by other MOF-based catalysts. This work enlightens a meticulous strategy to attain identified dual-metal catalytic sites and bridges the discrepancy between experimental study and theoretical insight.