A general route via formamide condensation to prepare atomically dispersed metal-nitrogen-carbon electrocatalysts for energy technologies
journal contributionposted on 2019-04-03, 10:55 authored by Guoxin Zhang, Yin Jia, Cong Zhang, Xuya Xiong, Kai Sun, Ruida Chen, Wenxing Chen, Yun Kuang, Lirong Zheng, Haolin Tang, Wen Liu, Junfeng Liu, Xiaoming Sun, Wen-Feng Lin, Hongjie Dai
Single-atom electrocatalysts (SAECs) have gained tremendous attention due to their unique active sites and strong metal–substrate interactions. However, the current synthesis of SAECs mostly relies on costly precursors and rigid synthetic conditions and often results in very low content of single-site metal atoms. Herein, we report an efficient synthesis method to prepare metal–nitrogen–carbon SAECs based on formamide condensation and carbonization, featuring a cost-effective general methodology for the mass production of SAECs with high loading of atomically dispersed metal sites. The products with metal inclusion were termed as formamide-converted metal–nitrogen–carbon (shortened as f-MNC) materials. Seven types of single-metallic f-MNC (Fe, Co, Ni, Mn, Zn, Mo and Ir), two bi-metallic (ZnFe and ZnCo) and one tri-metallic (ZnFeCo) SAECs were synthesized to demonstrate the generality of the methodology developed. Remarkably, these f-MNC SAECs can be coated onto various supports with an ultrathin layer as pyrolysis-free electrocatalysts, among which the carbon nanotube-supported f-FeNC and f-NiNC SAECs showed high performance for the O2 reduction reaction (ORR) and the CO2 reduction reaction (CO2RR), respectively. Furthermore, the pyrolysis products of supported f-MNC can still render isolated metallic sites with excellent activity, as exemplified by the bi-metallic f-FeCoNC SAEC, which exhibited outstanding ORR performance in both alkaline and acid electrolytes by delivering ∼70 and ∼20 mV higher half-wave potentials than that of commercial 20 wt% Pt/C, respectively. This work offers a feasible approach to design and manufacture SAECs with tuneable atomic metal components and high density of single-site metal loading, and thus may accelerate the deployment of SAECs for various energy technology applications.
This work was financially supported by the National Natural Science Foundation of China (NSFC, 21520102002, 91622116, 21471014, and 21701101), the National Key Research and Development Project (2016YFF0204402 and 2017YFA0206500), the Fundamental Research Funds for the Central Universities, the Long-Term Subsidy Mechanism from the Ministry of Finance and the Ministry of Education of China, the Shandong Scientific Research Awards Foundation for Outstanding Young Scientists (grant number ZR2018JL010), the Shandong Joint Fund of Outstanding Young Talents (grant number ZR2017BB018) and Loughborough University (H10841).
- Aeronautical, Automotive, Chemical and Materials Engineering
- Chemical Engineering