A team of researchers at National Taiwan University has made significant strides in understanding the selective conversion of carbon dioxide (CO2) into formate by copper chalcogenides. Their findings, published in Nature Communications on December 3, 2025, reveal a charge-redistribution mechanism that clarifies why these materials demonstrate remarkable efficiency in this process.
Copper chalcogenides have long fascinated scientists due to their unique catalytic properties. Traditionally, the conversion of CO2 into formate is associated with p-block metals like tin or bismuth, rather than transition metals such as copper (Cu), which typically lacks product selectivity. This breakthrough addresses a critical gap in knowledge about the intrinsic capabilities of copper chalcogenides.
Utilizing advanced operando synchrotron-based X-ray spectroscopic techniques, the research team successfully captured direct spectroscopic evidence of the underlying mechanisms at play. The study unveiled that chalcogenide anions play a dual role: they stabilize the catalytic structure of cuprous (Cu+) species, preventing their over-reduction to metallic copper (Cu0). This stabilization maintains an electronic configuration conducive to forming key intermediates, including carbon monoxide (CO) and formate.
Moreover, the findings indicate that these chalcogenide anions induce a vital charge-redistribution process within the Cu+ sites. This dynamic stabilization of O-bound formate intermediates effectively directs the CO2 reduction pathway toward formate formation, significantly suppressing competing CO and multi-carbon products.
The optimal catalyst identified in the research, CuS, demonstrated an impressive 90% faradaic efficiency for formate production at −0.6 V, with a formate partial current exceeding an ampere-scale. This level of performance showcases the potential scalability of copper chalcogenides for industrial applications, making them a promising option for carbon capture and conversion technologies.
Hao Ming Chen, a distinguished professor of chemistry and co-corresponding author of the study, remarked on the implications of the research: “Copper chalcogenides have fascinated researchers for decades because of their enhanced formate selectivity, but the true origin of this behavior was never fully understood. Our study reveals that charge-redistribution dynamics redefine the fundamental principles governing CO2 reduction selectivity and offer a new design strategy for tuning catalyst electronic structure via chalcogen modification.”
This research marks a pivotal advancement in the field of electrocatalysis, providing essential insights into how charge redistribution influences selective processes. The ongoing exploration of copper chalcogenides could lead to more efficient methods for carbon utilization, a critical factor in addressing global climate challenges.
For further details, refer to the publication by Feng-Ze Tian et al, titled “Charge redistribution dynamics in chalcogenide-stabilized cuprous electrocatalysts unleash ampere-scale partial current toward formate production,” available in Nature Communications (2025), DOI: 10.1038/s41467-025-64472-1.
