Electrochemical reduction of CO2 (CO2RR) provides an attractive pathway to achieve a carbon-neutral energy cycle. Single-atom catalysts (SAC) have shown unique potential in heterogeneous catalysis, but their structural simplicity prevents them from breaking linear scaling relationships. In this study, we develop a feasible strategy to precisely construct a series of electrocatalysts featuring well-defined single-atom and dual-site iron anchored on nitrogen-doped carbon matrix (Fe1–N–C and Fe2–N–C). The Fe2–N–C dual-atom electrocatalyst (DAC) achieves enhanced CO Faradaic efficiency above 80% in wider applied potential ranges along with higher turnover frequency (26,637 h–1) and better durability compared to SAC counterparts. Furthermore, based on in-depth experimental and theoretical analysis, the orbital coupling between the iron dual sites decreases the energy gap between antibonding and bonding states in *CO adsorption. This research presents new insights into the structure–performance relationship on CO2RR electrocatalysts at the atomic scale and extends the application of DACs for heterogeneous electrocatalysis and beyond.

Electrocatalysis undeniably offers noteworthy improvements to future energy conversion and storage technologies, such as fuel cells, water electrolyzers, and metal–air batteries. Molecular interaction between catalytic surfaces and chemical reactants produces...

We present a highly active CeO 2 -based catalyst for oxidizing CO in automobile exhaust. This catalyst was systemically designed by co-doping with transition metals (TMs). First, we used density functional theory (DFT) calculations to screen Mn and 13 dopant TMs (periods 4~6 in groups VIII~XI) and their 91 binary combinations for co-doping. As a result, Cu and (Cu, Ag) were found to be the best candidates among the single and binary dopants, respectively. Next, we synthesized CeO 2 nano-particles doped with Cu or (Cu, Ag), then experimentally confirmed that the predicted (Cu, Ag) co-doped CeO 2 showed higher activity than pure CeO 2 and other TM-doped CeO 2 . This was attributed to the easy formation of oxygen vacancies in the lattice of CeO 2 . Our study demonstrates that the use of a rational design of CeO 2 -based catalyst through theoretical calculations and experimental validation can effectively improve the low-temperature catalytic activity of CO oxidation.

Rare earth (RE) metals have often been used as dopants to improve the catalytic activity of ceria. However, their exact role in the activity of ceria catalyst has not been clearly identified. Combining experimental and theoretical approaches, we extensively investigate CO oxidation as a model reaction on RE-doped ceria (REC). The apparent activity is linearly proportional to the specific surface area (A S), which is enlarged by RE dopants as a consequence of surface stabilization. To decouple the effect of each RE dopant on the surface inherent activity, we set A S of REC to be almost constant by adjusting the pH during synthesis. In this case, however, pure ceria shows higher activity than any REC. We therefore conclude that although the RE dopants have lower intrinsic activity than that of Ce, they have an important effect of increasing A S to a level that pure ceria can never attain synthetically, thereby increasing their catalytic activity.

Single‐atom nanozymes (SAzymes) are promising in next‐generation nanozymes, nevertheless, how to rationally modulate the microenvironment of SAzymes with controllable multi‐enzyme properties is still challenging. Herein, we systematically investigate the relationship between atomic configuration and multi‐enzymatic performances. The constructed MnSA−N3‐coordinated SAzymes (MnSA−N3−C) exhibits much more remarkable oxidase‐, peroxidase‐, and glutathione oxidase‐like activities than that of MnSA−N4−C. Based on experimental and theoretical results, these multi‐enzyme‐like behaviors are highly dependent on the coordination number of single atomic Mn sites by local charge polarization. As a consequence, a series of colorimetric biosensing platforms based on MnSA−N3−C SAzymes is successfully built for specific recognition of biological molecules. These findings provide atomic‐level insight into the microenvironment of nanozymes, promoting rational design of other demanding biocatalysts.