Chem. J. Chinese Universities ›› 2025, Vol. 46 ›› Issue (7): 20250073.doi: 10.7503/cjcu20250073

• Physical Chemistry • Previous Articles    

Enhancing Methanol Oxidation Reaction by NiO Featuring High Concentration of Oxygen Vacancy and Ni3+/Ni2+ Ratio

LU Jiantian1, ZHAO Manzhen1, ZHANG Baohua1(), SONG Shuang2, ZHANG Yuwei1,2()   

  1. 1.Center for Advanced Analytical Science,Guangzhou Key Laboratory of Sensing Materials & Devices,Guangdong Engineering Technology Research Center for Photoelectric Sensing Materials and Devices,School of Chemistry and Chemical Engineering,Guangzhou University,Guangzhou 510006,China
    2.Guangzhou Key Laboratory of Analytical Chemistry for Biomedicine,GDMPA Key Laboratory for Process Control and Quality Evaluation of Chiral Pharmaceuticals,School of Chemistry,South China Normal University,Guangzhou 510006,China
  • Received:2025-03-14 Online:2025-07-10 Published:2025-04-16
  • Contact: ZHANG Yuwei E-mail:ccbhzhang@gzhu.edu.cn;ywzhang@scnu.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(22122402);the Natural Science Foundation of Guangdong Province, China(2021B1515020048);the Science and Technology Innovation Strategy of Guangdong Province, China(pdjh2024b303)

Abstract:

To address the critical challenges of insufficient active sites, poor conductivity, and sluggish reaction kinetics in nickel-based electrocatalysts for methanol oxidation reaction(MOR), this study proposes a lattice doping engineering strategy. By employing a low-cost ammonium molybdate precursor coupled with a calcination process, we successfully constructed Mo-doped NiO catalysts synergistically enhanced by oxygen vacancies and Ni³⁺ active sites. Experimental results demonstrate that as the Mo doping level increases from 0 to 28%(atomic fraction), the oxygen vacancy concentration on the catalyst surface escalates progressively from 30.18% to 56.59%, while the proportion of Ni3+ species rises from 65.55% to 85.91%. At an optimal Mo doping content of 28%, the catalyst achieves a current density of 280.8 mA/cm² at 1.7 V(vs. RHE) in 1.0 mol/L KOH/1.0 mol/L CH3OH electrolyte, representing a 12.9-fold enhancement compared to undoped NiO(21.7 mA/cm2). Furthermore, the Tafel slope decreases signifi-cantly from 63 mV/dec to 25 mV/dec. Systematic characterizations via XRD, SEM, TEM and XPS elucidate the formation mechanism of Mo-doped NiO catalysts with tunable oxygen vacancy concentrations and Ni³⁺/Ni²⁺ ratios, as well as their MOR electrocatalytic performance. A preliminary structure-activity relationship is established, revealing the underlying principles of enhanced activity. This work provides a novel approach for designing efficient anode catalysts for direct methanol fuel cells(DMFCs) with high active site density.

Key words: Oxygen vacancy, Methanol oxidation reaction, Mo-doping

CLC Number: 

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