Investigating the active sites in molybdenum anchored nitrogen-doped carbon for alkaline oxygen evolution reaction

Yuan Wang; Rui Dong; Pengfei Tan; Hongqin Liu; Hanxiao Liao; Min Jiang; Yong Liu; Lu Yang; Jun Pan

doi:10.1016/j.jcis.2021.11.058

Investigating the active sites in molybdenum anchored nitrogen-doped carbon for alkaline oxygen evolution reaction

J Colloid Interface Sci. 2022 Mar:609:617-626. doi: 10.1016/j.jcis.2021.11.058. Epub 2021 Nov 15.

Authors

Yuan Wang¹, Rui Dong¹, Pengfei Tan², Hongqin Liu¹, Hanxiao Liao¹, Min Jiang¹, Yong Liu¹, Lu Yang³, Jun Pan⁴

Affiliations

¹ State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, PR China.
² State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, PR China. Electronic address: tpf0203@csu.edu.cn.
³ Hunan provincial Collaborative Innovation Center for Environment and Energy Photocatalysis, Changsha University, Changsha 410083, PR China.
⁴ State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, PR China. Electronic address: jun.pan@csu.edu.cn.

PMID: 34801237
DOI: 10.1016/j.jcis.2021.11.058

Abstract

Developing durable and efficient non-precious-metal based catalysts for oxygen evolution reaction (OER) is highly desirable in the field of electrocatalysis. In this work, a series of novel Mo anchored N-doped carbon catalysts (denoted as Mo/NC-T) were prepared starting from the zeolitic imidazolate framework 8 (ZIF-8) precursor. Firstly, Mo doped ZIF-8 precursor (Mo/ZIF-8) with a regular polyhedron structure was formed through a simple ion-exchange method process between molybdenum pentachloride (MoCl₅) and ZIF-8. Afterward, Mo/ZIF-8 was converted to Mo/NC-T through a two-step calcination process in nitrogen (N₂) and ammonia (NH₃). The as-synthesized Mo/NC-T samples exhibited superior electrocatalytic OER properties. The optimal sample at 650 °C (Mo/NC-650) presented a low overpotential of 320 mV at 10 mA cm^-2, a Tafel slope of 71 mV dec^-1, and an outstanding long-term stability for 30 h in 1 M KOH solution. The remarkable OER activity of Mo/NC-T could be ascribed to the structural stability of carbon matrix and the synergistic effect between Mo³⁺ (derived from Mo-C bonds) and pyridinic N. This work provides a novel perspective on the roles of Mo species in the N-doped carbon electrocatalysts for OER.

Keywords: Active sites; Mo-C bonds; Nitrogen doped carbon materials; Oxygen evolution reaction.