(514d) Isolated Heteronuclear Diatomic Pair and Controlling Their Supports’ Morphology for Highly Active CO2 Electroreduction

Single atom catalysts have emerged as great potential in electrochemical CO₂ reduction reaction(CO₂RR). Until recently, research has been mostly focused on single atom catalysts, and it remains a great challenge to synthesize bimetallic dimer structures, which provide more concentrated active centers compared with single atom catalysts. Herein, we construct a novel isolated diatomic Ni-Zn pair electrocatalyst, showing a high CO selectivity of 97%. Industrial current density reaches above 300 milliamperes per square centimeter at a low potential of -0.5 volts versus a reversible hydrogen electrode(RHE) in flow cell. X-ray absorption spectroscopy indicates that the Ni-Zn dimer structure model contains one Ni-Zn bonding configuration. First principle calculations reveal that the diatomic Ni-Zn pair generate a synergy effect by modulating the electronic structure, which results in the enhanced CO₂ electroreduction activity. Operational stability and current density was enhanced via the introduction of a polymer-based gas diffusion layer.

Another work about the role of support’s morphological attributes was investigated. Most of atom-dispersed catalysts are anchored on amorphous carbon-based supports. The morphology of support is often overlooked. Herein, We prepared mesoporous nitrogen-doped carbon foam nanospheres with different pore sizes as supports of atom-dispersed catalysts. We found that the activity was increased by introducing the porosity into the carbon structure, and supports with pore sizes of 20-30nm are the most optimum for single-atom catalyst during carbon dioxide reduction. Computer simulation results obtained from the model agree with experiments. These works pave the way for the rational design of current catalysts with good activity and stability, which have a great potential to be applied in various catalytic reactions.