The continued consumption of fossil fuels and the increasing carbon and nitrogen emissions caused by human activities have drawn global attention to the energy and environmental crisis. Developing sustainable strategies to achieve the carbon and nitrogen cycle is essential to overcome these issues. Electrocatalytic reactions powered by renewable energy sources have emerged as promising ways to alleviate these problems while producing valuable chemicals. For example, electrochemical CO2 reduction (CO2RR) to hydrocarbons and oxygenates, and electrocatalytic NO3 reduction reaction (NITRR) to produce ammonia. These electrochemical processes involve complex multi-electron transfer reactions with limitations in terms of kinetics and thermodynamics.
For CO2RR, the selectivity and reaction rate of the C2 product are low due to the slow thermodynamics and kinetics of C-C coupling;Nitrr typically involves a complex process of 9 protons and 8 electrons (NO3 +9H++8E NH3+3H2O) and also affects the selectivity and current density of ammonia. Therefore, it is necessary to further develop efficient and economical electrocatalysts for CO2RR and NITRR to promote the practical application of CO2RR and NITRRR.
Recently,Ye Ruquan, City University of Hong KongHong Kong University of Science and Technology Tang BenzhongRice University Boris I yakobsonPhilip Xi, Agency for Science, Technology and Research, SingaporeZhu Minghui, East China University of Science and TechnologyThe CUXO bipyramid with controllable angle and abundant nanoparticles was synthesized by laser-assisted fabrication technology, and elucidated the mechanism of how the synergy of electric field and interface plays a role in bifunctional electrochemical CO2RR and NITRR by controlling electron transport and ion concentration.
Taking electrochemical CO2RR as an example, the sharp tip geometry of the CUXO generates a strong local electric field, which improves electron transport and ion concentration, and dynamically regulates the reaction microenvironmentAt the same time, the abundant Cu+ Cu2+ interface provides a large number of active sites, reduces the reaction barrier, and promotes the formation of *OC-COH, thereby thermodynamically promoting the reduction reaction, and the combination of the two effects leads to excellent catalytic performance. More importantly, the field effect and nanoparticle interface are also conducive to improving the electrochemical NITRR activity.
The performance test results show that the flow density of the C2+ part of the optimal L-CUXO-HC is 665The Faraday efficiency (Fe) of 9 mA cm-2, CO2RR is 81%;At the same time, the NH3 yield of the catalyst is 8183 mg H-1 mg-1, NH3 partial flow density of more than 600 mA cm-2, better than the catalyst reported in the current literature. In addition, L-Cuxo-HC has potential application value as a bifunctional catalyst in the green chemical industry, which can convert wastewater and waste gas into valuable products. Overall, the combination of finite element simulations and density functional theory (DFT) calculations provides an in-depth understanding of locally enhanced electric fields and interfacial active sites, and the proposed laser synthesis method will also inspire the design of the next generation of multi-electron reduction catalysts for carbon and nitrogen cycling.
accelerating multielectron reduction at cuxo nanograins interfaces with controlled local electric field. nature communications, 2023. doi: 10.1038/s41467-023-43303-1