Synergizing Inter and Intraband Transitions in Defective Tungsten Oxide for Efficient Photocatalytic Alcohol Dehydration to Alkenes

Meilin Duan; Canyu Hu; Hao Li; Yihong Chen; Ruitian Chen; Wanbing Gong; Zhou Lu; Ning Zhang; Ran Long; Li Song; Yujie Xiong

doi:10.1021/jacsau.2c00146

Synergizing Inter and Intraband Transitions in Defective Tungsten Oxide for Efficient Photocatalytic Alcohol Dehydration to Alkenes

JACS Au. 2022 May 13;2(5):1160-1168. doi: 10.1021/jacsau.2c00146. eCollection 2022 May 23.

Authors

Meilin Duan^{1

2}, Canyu Hu¹, Hao Li³, Yihong Chen¹, Ruitian Chen¹, Wanbing Gong¹, Zhou Lu³, Ning Zhang⁴, Ran Long¹, Li Song¹, Yujie Xiong^{1

2

3}

Affiliations

¹ School of Chemistry and Materials Science, and National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, China.
² Institute of Energy, Hefei Comprehensive National Science Center, 350 Shushanhu Road, Hefei, Anhui 230031, China.
³ Anhui Province Key Laboratory of Optoelectronic Material Science and Technology, School of Physics and Electronic Information, Anhui Engineering Research Center of Carbon Neutrality, Anhui Normal University, Wuhu, Anhui 241002, China.
⁴ Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong 999077, China.

Abstract

Photocatalysis under mild conditions is an intriguing avenue for organic chemical manufacturing to confront the serious fossil energy crisis. Herein, we report a direct light-driven alkene production through alcohol dehydration, using nonstoichiometric tungsten oxide of W₁₈O₄₉ nanowires with abundant lattice defects as a photocatalyst. A representative ethylene (C₂H₄) production rate of 275.5 mmol g_cat ^-1 h^-1 is achieved from ethanol (C₂H₅OH) dehydration, together with excellent selectivity up to 99.9%. The universality of our approach is further demonstrated with other alcohol dehydration. Combining ultrafast transient absorption spectroscopy with in situ X-ray photoelectron spectroscopy, we underline that the inter- and intraband transitions synergistically contribute to such excellent activity. In particular, the intraband transition excites the electrons in defect bands into an energetically "hot" state, largely alleviating the charge recombination. As a result, the C-OH bond of chemisorbed C₂H₅OH molecules can be effectively dissociated to furnish the formation of C=C bonds. Our work offers a fresh insight into sustainable alkene production with renewable energy input under mild conditions.