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:10.1038/s41467-024-48866-1

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

Nat Commun. 2024 May 24;15(1):4453. doi: 10.1038/s41467-024-48866-1.

Authors

Huizhen Zhang^#¹, Pengfei Sun^#¹, Xiaozhen Fei¹, Xuejiao Wu¹, Zongyi Huang¹, Wanfu Zhong¹, Qiaobin Gong¹, Yanping Zheng¹, Qinghong Zhang¹, Shunji Xie^{2

3}, Gang Fu^{4

5}, Ye Wang^{6

7}

Affiliations

¹ State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, National Engineering Laboratory for Green Chemical Productions of Alcohols, Ethers and Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China.
² State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, National Engineering Laboratory for Green Chemical Productions of Alcohols, Ethers and Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China. shunji_xie@xmu.edu.cn.
³ Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen, China. shunji_xie@xmu.edu.cn.
⁴ State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, National Engineering Laboratory for Green Chemical Productions of Alcohols, Ethers and Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China. gfu@xmu.edu.cn.
⁵ Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen, China. gfu@xmu.edu.cn.
⁶ State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, National Engineering Laboratory for Green Chemical Productions of Alcohols, Ethers and Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China. wangye@xmu.edu.cn.
⁷ Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen, China. wangye@xmu.edu.cn.

^# Contributed equally.

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.

Abstract

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