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<p>Dry reforming of methane over Ni catalysts offers a route to convert CH<sub>4</sub> and CO<sub>2</sub> into syngas while using two greenhouse gases, but its performance is limited by carbon deposition and poorly understood metal support effects. Here, density functional theory with DFT + U+D2 is used to study a Ni dimer (Ni2) supported on α Al<sub>2</sub>O<sub>3</sub>(0001) and hydroxylated α Al<sub>2</sub>O<sub>3</sub> OH(0001). After validating the structural model against reference data, we examine adsorption of CH<sub>4</sub>, CO<sub>2</sub>, CO, H<sub>2</sub>, and atomic C on bare and Ni-supported surfaces. CH<sub>4</sub> and H<sub>2</sub> show weak, nearly system-independent physisorption, indicating that their activation must occur mainly in the transition states. In contrast, CO<sub>2</sub> and CO are strongly chemisorbed and activated at Ni Al<sub>2</sub>O<sub>3</sub> interfaces, especially on the hydroxylated surface, where large adsorption energies, strong bending, and marked charge transfer are found. Atomic carbon is very strongly stabilized at the same interfacial sites. Analysis of projected density of states, Mulliken charges and electron density differences identifies the Ni alumina perimeter as the key region governing CO<sub>2</sub> activation and coke formation in Ni-based DRM catalysts.</p>

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DFT investigation of CO₂ activation and carbon trapping at Ni/Al₂O₃ interfaces in dry reforming of methane

  • 期刊论文

  • 出版模式：

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  • 发表日期：

    2026年7月27日

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  • Salah Sakrane,
  • Oualid Alioui,
  • Leila Dehimi,
  • Marco Balsamo,
  • Alessandro Erto,
  • Mohammed Alamro,
  • Malik Albrahim,
  • K. S. Abdel Halim,
  • Byong-Hun Jeon,
  • Hyun-Jo Ahn,
  • Yacine Benguerba

摘要

Dry reforming of methane over Ni catalysts offers a route to convert CH4 and CO2 into syngas while using two greenhouse gases, but its performance is limited by carbon deposition and poorly understood metal support effects. Here, density functional theory with DFT + U+D2 is used to study a Ni dimer (Ni2) supported on α Al2O3(0001) and hydroxylated α Al2O3 OH(0001). After validating the structural model against reference data, we examine adsorption of CH4, CO2, CO, H2, and atomic C on bare and Ni-supported surfaces. CH4 and H2 show weak, nearly system-independent physisorption, indicating that their activation must occur mainly in the transition states. In contrast, CO2 and CO are strongly chemisorbed and activated at Ni Al2O3 interfaces, especially on the hydroxylated surface, where large adsorption energies, strong bending, and marked charge transfer are found. Atomic carbon is very strongly stabilized at the same interfacial sites. Analysis of projected density of states, Mulliken charges and electron density differences identifies the Ni alumina perimeter as the key region governing CO2 activation and coke formation in Ni-based DRM catalysts.