镍单原子催化剂的制备及其电催化CO_(2)还原研究

Preparation and electrocatalytic CO_(2) reduction of Ni-based single-atom catalyst

电催化CO_(2)还原反应(Electrocatalytic CO_(2)reduction reaction, CO_(2)RR)在解决全球变暖和能源危机方面有着巨大的应用潜力,但目前催化效率低、催化产物多样等问题限制了CO_(2)RR反应的商业化应用。采用一锅法、碳化法制备了一系列不同镍含量的镍单原子催化剂,利用XRD、XPS、ICP-OES、HRTEM、HAADF-STEM、XAS等方法对镍单原子催化剂的形貌结构、原子价态、金属含量等方面进行表征,并通过电催化还原产物的法拉第效率(Faraday efficiency, FE)和电流密度(Current density,J)来评价其电催化性能。此外,还研究了电解实验装置的改变对升电催化性能的提升。实验结果表明,随着Ni单原子催化剂的Ni金属负载量增加,产物CO的FECO和JCO均增加。催化剂中Zn1Ni2-CN表现出了优异的CO_(2)RR催化性能,在H型电解池中,在-0.7 V vs. RHE电位下FECO达到89%,在-0.9 V vs. RHE下JCO达到6.99 mA·cm^(-2)。在流动电解池中,大范围电位变化下(-0.4~-1.2 V vs. RHE)FECO均保持在99%以上,且在-1.2 V vs. RHE电位下产物电流密度JCO达到174.5 mA·cm^(-2)。

Electrocatalytic CO_(2) reduction reaction(CO_(2) RR)has great application potential in solving global warming and the energy crisis,but the current problems such as low catalytic efficiency and diverse catalytic products limit the commercial application of CO_(2) RR reaction.A series of nickel single-atom catalysts with different nickel contents were prepared by a one-pot carbonization method.The morphology,structure,atomic valence state,and metal content of nickel single-atom catalysts were characterized by XRD,XPS,ICP-OES,HRTEM,HAADF-STEM,XAS and other methods.The electrocatalytic performance was evaluated by the Faradaic efficiency(FE)and current density(J)of the electrocat-alytic reduction products.The electrocatalytic performance was improved by changing the electrolysis ex-perimental device.The experimental results indicated that both FECO and JCO increased as the Ni metal loading of Ni single-atom catalysts increased.Zn1 Ni2-CN in the catalyst exhibited excellent CO_(2) RR cata-lytic performance.In the H-type electrolytic cell,the FECO reached 89%at-0.7 V vs.RHE,and the JCO reached 6.99 mA·cm^(-2) at-0.9 V vs.RHE.From-0.4 to-1.2 V vs.RHE in the flow electrolytic cell,FECO remained above 99%,and JCO reached 174.5 mA·cm^(-2) at-1.2 V vs.