Nature Communications (May 2024)

Unusual facet and co-catalyst effects in TiO2-based photocatalytic coupling of methane

  • Huizhen Zhang,
  • Pengfei Sun,
  • Xiaozhen Fei,
  • Xuejiao Wu,
  • Zongyi Huang,
  • Wanfu Zhong,
  • Qiaobin Gong,
  • Yanping Zheng,
  • Qinghong Zhang,
  • Shunji Xie,
  • Gang Fu,
  • Ye Wang

DOI
https://doi.org/10.1038/s41467-024-48866-1
Journal volume & issue
Vol. 15, no. 1
pp. 1 – 10

Abstract

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Abstract Photocatalytic coupling of methane to ethane and ethylene (C2 compounds) offers a promising approach to utilizing the abundant methane resource. However, the state-of-the-art photocatalysts usually suffer from very limited C2 formation rates. Here, we report our discovery that the anatase TiO2 nanocrystals mainly exposing {101} facets, which are generally considered less active in photocatalysis, demonstrate surprisingly better performances than those exposing the high-energy {001} facet. The palladium co-catalyst plays a pivotal role and the Pd2+ site on co-catalyst accounts for the selective C2 formation. We unveil that the anatase {101} facet favors the formation of hydroxyl radicals in aqueous phase near the surface, where they activate methane molecules into methyl radicals, and the Pd2+ site participates in facilitating the adsorption and coupling of methyl radicals. This work provides a strategy to design efficient nanocatalysts for selective photocatalytic methane coupling by reaction-space separation to optimize heterogeneous-homogeneous reactions at solid-liquid interfaces.