Interface-Transferring Electrons and Photogenerated Carriers in W₁₈O₄₉/N-Doped C to Boost Photothermocatalytic Ethanol Dehydration to Ethylene

Ethanol, a biomass-derived platform molecule, can be converted into high-value products like ethylene via photothermocatalysis, offering a sustainable alternative to petroleum processes. Yet, further enhancement of catalytic performance needs the rational modulation of electronic concentration at the active site. Herein, we design a W18O49/nitrogen-doped carbon (NC) catalyst that uniquely integrates two distinct electrons: (i) directional electron transfer from NC to W18O49, and (ii) photogenerated carriers generated by W18O49 itself under light irradiation. This dual-channel electronic configuration enables efficient ethylene production from the ethanol dehydration reaction over an optimal W18O49/NC catalyst, achieving a 76.4 mmol gcat.–1 yield (62.3% conversion with nearly 100% selectivity for ethylene), which is 2.2-fold that of pristine W18O49 under identical irradiation conditions. Detailed characterization using electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy (XPS) reveals that the interaction between interface-transferring electrons from the NC support and photogenerated carriers generates electron-rich active sites, thereby promoting C–O bond cleavage and facilitating the ethanol dehydration reaction. Apparent activation energy tests and in situ Fourier transform infrared spectroscopy (FTIR) further demonstrate that interface-transferred electrons from the NC support play a more significant role in ethanol activation than photogenerated carriers. This study provides valuable insights into the mechanism of photothermocatalytic ethanol dehydration and offers a new strategy for the rational design of more efficient photothermal catalysts.