The single-atom catalysts immobilized on nitrogen-doped carbon supports (M-N/C) have been widely used for CO2 electrocatalytic reduction reaction due to their high atom utilization efficiency.
Recently, a research team led by Prof. LIU Licheng from the Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT) of the Chinese Academy of Sciences (CAS) proposed a two-step amination strategy to regulate the electronic structure of M-N/C catalysts (M=Ni, Fe, Zn) and enhance the intrinsic activity of CO2 electrocatalytic reduction.
In the strategy, the M-N4/C was aminated by annealing with carbamide in NH3, impregnation and hydrothermal reaction in ammonia water to synthesize final M-N4/C-NH2 catalysts.
Although M-N/C catalysts are widely used, they demonstrate a poor reaction current density, which is much worse than the current density of industrial level.
In the study, the researchers used gas diffusion electrodes to create a reactive three-phase interface in a flow electrolyzer to increase the current density for CO production to industrial application level.
The aminated Ni single-atom catalyst demonstrated a remarkable current density of >400 mA cm-2 with a nearly 90% Faraday efficiency for CO production, which is 1.8 times of that before amination.
The study, published in Energy & Environmental Science, provides a method for increasing current density at industrial-relevant level of single-atom catalysts.
This work was supported by the National Natural Science Foundation of China, Dalian National Laboratory for Clean Energy Cooperation Fund, Special Research Assista